Small molecule antagonists of bcl-2 family proteins

ABSTRACT

The present invention relates to naturally occurring and chemically synthesized small molecule antagonists of Bcl-2 family proteins. In particular, the present invention provides gossypol compounds (e.g., isomers, enantiomers, racemic compounds, metabolites, derivatives, pharmaceutically acceptable salts, in combination with acids or bases, and the like) and methods of using these compounds as antagonists of the anti-apoptotic effects of Bcl-2 family member proteins (e.g., Bcl-2, Bcl-X L , and the like). The present invention also provides compositions comprising gossypol compounds and optionally one or more additional therapeutic agents (e.g., anticancer/chemotherapeutic agents). The present invention also provides methods for treating diseases and pathologies (e.g., neoplastic diseases) comprising administering a composition comprising gossypol compounds and optionally one or more additional therapeutic agents (e.g., anticancer/chemotherapeutic agents) and/or techniques (e.g., radiation therapies, surgical interventions, and the like) to a subject or in vitro cells, tissues, and organs.

This application is a continuation in part of U.S. patent applicationSer. No. 10/158,769 filed May 30, 2002, and PCT/US02/17206 filed May 30,2002, both of which claim priority to U.S. Provisional PatentApplication Ser. No. 60/293,983, filed May 30, 2001, the contents ofeach of which are fully incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to naturally occurring and chemicallysynthesized small molecule antagonists of Bcl-2 family proteins. Inparticular, the present invention provides gossypol compounds (e.g.,isomers, enantiomers, racemic compounds, metabolites, derivatives,pharmaceutically acceptable salts, in combination with acids or bases,and the like) and methods of using these compounds as antagonists of theanti-apoptotic effects of Bcl-2 family member proteins (e.g., Bcl-2,Bcl-X_(L), and the like). The present invention also providescompositions comprising gossypol compounds and optionally one or moreadditional therapeutic agents (e.g., anticancer/chemotherapeuticagents). The present invention also provides methods for treatingdiseases and pathologies (e.g. neoplastic diseases) comprisingadministering a composition comprising gossypol compounds and optionallyone or more additional therapeutic agents (e.g.,anticancer/chemotherapeutic agents) and/or techniques (e.g., radiationtherapies, surgical interventions, and the like) to a subject or invitro cells, tissues, and organs.

BACKGROUND OF THE INVENTION

Multicellular organisms use a process called apoptosis to instructdamaged or unnecessary cells to destroy themselves for the good of theorganism. Control of the apoptotic process is very important for thenormal development of the organism. For example, fetal development offingers and toes requires the controlled removal, by apoptosis, ofexcess interconnecting tissues, as does proper formation of neuralsynapses within the brain. Careful control of apoptosis is alsoimportant to adult organisms, for instance, controlled apoptosis isresponsible for the sloughing of the inner lining of the uterus (theendometrium) at the start of menstruation.

Apoptosis not only plays an important role in tissue sculpting duringfetal development and normal cellular maintenance, it is also theprimary defense against rogue cells that threaten the well being of theentire organism. For instance, in the cell mediated immune response,effector cells (e.g., cytotoxic T lymphocytes “CTLs”) destroyvirus-infected host cells by inducing the infected host cells to undergoapoptosis. The organism subsequently relies in turn upon the apoptoticprocess to destroy the effector cells when they are no longer needed.Autoimmunity is prevented by the CTLs inducing apoptosis in each otherand even in themselves. Defects in this process are associated with avariety of autoimmune diseases such as lupus erythematosus andrheumatoid arthritis.

Multicellular organisms use the apoptotic process to instruct cells withdamaged nucleic acids (e.g., DNA) to destroy themselves prior tobecoming cancerous. However, some cancer-causing viruses preventapoptosis in transformed cells. For example, several human papillomaviruses (HPVs) are implicated in causing cervical cancer by suppressingapoptotic removal of transformed cells through the production of aprotein, E6, which inactivates the p53 apoptosis promoter. Epstein-Barrvirus (EBV), the causative agent of mononucleosis and Burkitt'slymphoma, a solid tumor of B lymphocytes, produces a first proteinsimilar to Bcl-2, and a second that causes transformed cells to increaseproduction of Bcl-2. The expression of various Bcl-2 family proteinshelps virus-transformed cells resist apoptosis. Still other virusesmanipulate the cell's apoptotic machinery without directly resulting inthe development of a cancer. For example, destruction of the immunesystem in individuals infected with the human immunodeficiency virus(HIV) is thought to progress through infected CD4+ T cells (about 1 in100,000) instructing their sister cells to undergo apoptosis. Faultyregulation of the apoptotic machinery has also been implicated invarious degenerative conditions and vascular diseases.

Some cancers that arise by non-viral means have also developedmechanisms to escape destruction by apoptosis. Melanoma cells, forinstance, avoid apoptosis by inhibiting the expression of the geneencoding the apoptosis effector protein Apaf-1. Other cancers,especially lung and colon, secrete elevated levels of soluble decoymolecules that bind FasL, inhibiting it from binding to Fas. CTLs arethus prohibited from destroying these cancer cells. Other cancer cellsexpress high levels of FasL, again, avoiding destruction by the CTLs.

It is apparent that the controlled regulation of the apoptotic processand the apoptotic machinery is vital to the survival of multicellularorganisms. Typically, the biochemical changes that occur in a cellinstructed to undergo apoptosis occur in an orderly procession. However,as shown above, flawed regulation of these process can cause seriousharm.

There have been various attempts to use small molecules to control andrestore regulation of the apoptotic machinery in aberrant cells (e.g.,cancer cells). Generally, these attempts have had limited success astreatments for the underlying diseases for a number of reasons,including high toxicity, low bioavailability, high costs, and the like.What is needed are improved methods and compositions for regulatingapoptosis in subjects afflicted with diseases and conditions that arecharacterized by faulty regulation of the apoptotic process.

SUMMARY OF THE INVENTION

It is generally accepted in the field of molecular oncology that most,if not all, malignant cancer cells harbor (at a minimum) twoderangements that lead to the malignant phenotype: a proliferativelesion, causing cells to multiply inappropriately, and an apoptoticlesion, that prevents the cell(s) from executing the apoptosis programin response to either the detection, within the cell, of these geneticabnormalities (e.g., up-regulation of a growth or mitosis oncogene likeRas or Myc), or the pharmacological effects of cell death-inducingcancer therapeutic drugs or radiation therapy. The apoptotic lesionconfers on the cells a survival advantage in the face of either furtheraccumulated oncogenic lesions, or exposure to pharmacologicallyeffective levels of cancer therapeutic drugs or radiation therapy.

A number of apoptotic lesions have been described in tumor cells (e.g.loss of p53, decreased Apaf-1, increased IAPs, decreased caspases), bothin vitro and in vivo, most notably enhanced expression and accumulationof proteins of the anti-apoptotic Bcl-2 gene family. Bcl-2 is theprototypical member of this family, which includes Bcl-X_(L), Mcl-1, A1,and Boo/Diva proteins. Bcl-2 is a human oncogene that prevents theactivation of the apoptosis program in many cells, and when expressed atinappropriately high levels in cancerous or pre-cancerous cells, conferson them a selective advantage. Bcl-2 and Bcl-X_(L) are overexpressed inmany types of human cancer (e.g., breast, prostate, colorectal, lung,etc.), including Non-Hodgkin's lymphoma, which is caused by achromosomal translocation (t14, 18) that leads to overexpression ofBcl-2, suggesting that many cancer cell types depend on the elevatedlevels of Bcl-2 and/or Bcl-X_(L) to survive the other cellularderangements that simultaneously both define them as cancerous orpre-cancerous cells and cause them to attempt to execute the apoptosispathway. Also, increased expression of Bcl-2 family proteins has beenrecognized as a basis for the development of resistance to cancertherapeutic drugs and radiation that act in various ways to induce celldeath in tumor cells.

The induction of apoptosis in cancer cells or their supporting cells(e.g., neovascular cells in the tumor vasculature) is thought to be auniversal mechanism of action for virtually all of the effective cancertherapeutic drugs or radiation therapies on the market or in practicetoday. The present invention contemplates that exposure of humanssuffering from cancer to therapeutically effective amounts of drug(s)(e.g., small molecules) that inhibit the function(s) of Bcl-2 andBcl-X_(L) kills cancer cells or supporting cells outright (those cellswhose continued survival is dependent on the overactivity of Bcl-2 orBcl-X_(L)) or to render such cells as a population more susceptible tothe cell death-inducing activity of cancer therapeutic drugs orradiation therapies. The present invention contemplates that inhibitorsof Bcl-2/Bcl-X_(L) satisfy an unmet need for the treatment of multiplecancer types, either when administered as monotherapy to induceapoptosis in cancer cells dependent on Bcl-2/Bcl-X_(L) function, or whenadministered in a temporal relationship with other cell death-inducingcancer therapeutic drugs or radiation therapies so as to render agreater proportion of the cancer or supportive cells vulnerable toexecuting the apoptosis program compared to the corresponding proportionof cells in a subject treated only with the cancer therapeutic drug orradiation therapy alone.

During the course of the development of the present invention, gossypolwas found to bind to a key binding site (the BH3-binding site) in bothBcl-2 and Bcl-X_(L), to which the natural protein antagonists ofBcl-2/Bcl-X_(L), including Bax, Bak, Bad, Bim, NOXA, and PUMA bind.Thus, particularly preferred embodiments provide compositions andmethods comprising gossypol compounds (e.g., (−)-gossypol, (−)-gossypolacetic acid, and the like) having Bcl-2/B Bcl-X_(L) inhibitory activity,and that cause cells that depend for their survival, at least in part,on Bcl-2 and/or Bcl-X_(L) to execute the apoptosis program and die. Thepresent invention is not limited to a particular mechanism. Indeed, anunderstanding of the mechanism is not necessary to practice (make anduse) the present invention. Nonetheless, it is contemplated that twoclasses of such Bcl-2/Bcl-X-dependent cells are 1) a first class ofcells that are internally deranged to such an extent that the “flux”through the apoptosis pathway would be sufficient, were it not for theelevated levels of Bcl-2 and/or Bcl-X_(L), to trigger execution of theapoptosis program; and 2) a second class of cells whose apoptosisprogram has been stimulated in response to a cancer therapeutic drug orradiation but below a threshold that has been set in that cell by theelevated levels of Bcl-2/Bcl-X_(L). Either class of cells, by virtue ofbeing dependent on Bcl-2, Bcl-X or both for their survival, can bekilled by an effective amount of a Bcl-2/Bcl-X_(L) inhibiting compound(e.g., (−)-gossypol, (−)-gossypol acetic acid, and the like).

Indeed, gossypol compounds (e.g., (−)-gossypol) can induce the death oftumor cells in vitro and can reduce tumor burden in mice bearing humantumor xenografts (See, Examples). In addition, gossypol compounds (e.g.,(−)-gossypol), by virtue of reducing the activity of Bcl-2 and/orBcl-X_(L) in cancer cells or supporting cells, increases the proportionof cells in a subject that will respond to the cell-damaging effects ofcancer therapeutic drugs or radiation therapy by executing the apoptosisprogram, leading to a greater tumor response in subjects treated incombination with gossypol and the cancer therapeutic drug or radiationtherapy compared to those treated with chemo/radiation alone. Thisenhanced tumor response will be reflected in any of a number ofclinically desirable endpoints, including tumor shrinkage and/or loss,time to tumor progression (TTP), or survival. In additional preferredembodiments, gossypol compounds (e.g., (−)-gossypol), in combinationwith any of a number of cancer therapeutic drugs or radiation, producesadded tumor reductions over chemo/radiation alone (See, Examples). Insome examples, gossypol compounds (e.g., (−)-gossypol) produce“synergistic” apoptosis (in vitro isobologram Examples) or tumorresponses (in vivo Examples). The in vivo synergism even leads, in somecases, to regression of tumors that would not regress with either agentalone.

From these observations, combination treatment of human subjects with atherapeutically effective amount of a gossypol compound (e.g.,(−)-gossypol) and an approved course of cancer therapeutic drugs orradiation, produces a greater tumor response and clinical benefit insuch subjects compared to those treated with gossypol compound or cancerdrugs/radiation alone. It is contemplated that gossypol (e.g.,(−)-gossypol) acts either to kill cells outright or to increase theproportion of cancer or supporting cells that respond to theapoptosis-inducing effects of drugs/radiation by executing the apoptosisprogram. Put another way, because gossypol compounds lower the apoptoticthreshold of all cells that express Bcl-2 and/or Bcl-X_(L), theproportion of cells that successfully execute the apoptosis program inresponse to the apoptosis-inducing activity of cancer drugs/radiation isincreased. Alternatively, gossypol compounds can be used to allowadministration of a lower, and therefore less toxic and more tolerable,dose of a cancer therapeutic drug or radiation to produce the same tumorresponse/clinical benefit as the conventional dose of the drug/radiationalone. Since the doses for all approved cancer drugs and radiationtreatments are known, the present invention contemplates the variouscombinations of them with gossypol compounds. Also, since gossypolcompounds act at least in part by inhibiting Bcl-2 and/or Bcl-X_(L), theexposure of cancer and supporting cells to a therapeutically effectiveamount of gossypol can be temporally linked to coincide with theattempts of cells to execute the apoptosis program in response to thecancer drug or radiation therapy. Thus, in some embodiments,administering the compositions and methods of the present invention inview of certain temporal relationships, which can be tested in clinicaltrials, provides especially efficacious therapeutic practices.

The present invention relates to naturally occurring and chemicallysynthesized small molecule antagonists of Bcl-2 family proteins. Inparticular, the present invention provides gossypol compounds (e.g.,isomers, enantiomers, racemic compounds, metabolites, derivatives,pharmaceutically acceptable salts, in combination with acids or bases,and the like) and methods of using these compounds as antagonists of theanti-apoptotic effects of Bcl-2 family member proteins (e.g., Bcl-2,Bcl-X_(L), and the like). The present invention also providescompositions comprising gossypol compounds and optionally one or moreadditional therapeutic agents (e.g., anticancer/chemotherapeuticagents). The present invention also provides methods for treatingdiseases and pathologies (e.g., neoplastic diseases) comprisingadministering a composition comprising gossypol compounds and optionallyone or more additional therapeutic agents (e.g.,anticancer/chemotherapeutic agents) and/or techniques (e.g., radiationtherapies, surgical interventions, and the like) to a subject or invitro cells, tissues, and organs.

The term cancer is generally used to described hundreds of neoplasticdiseases and neoplasias. The neoplastic growths can be benign ormalignant. There are three broad types of cancer: carcinomas, sarcomas,and hematologic malignancies (more commonly known as lymphomas andleukemias). Each type of cancer can affect almost any organ or part ofthe body. Carcinomas originate in the outer layer of cells of the skinand internal membranes (e.g., breasts, lungs, intestines, skin,prostate, etc.). Sarcomas arise from connective tissue such as bone,muscle, cartilage and blood vessels. Lymphomas and leukemias,hematologic cancers, arise in the blood or blood-forming organs such asthe spleen, lymph nodes and bone marrow.

Cancer cells include tumor cells, neoplastic cells, malignant cells,metastatic cells, and hyperplastic cells. Neoplastic cells can be benignor malignant. Neoplastic cells are benign if they do not invade ormetastasize. A malignant cell is one that is able to invade and/ormetastasize. Hyperplasia is a pathologic accumulation of cells in atissue or organ, without significant alteration in structure orfunction.

Malignant tumors are generally referred to as being either primary orsecondary. Primary tumors arise directly in the tissue in which they arefound. Secondary tumors, or metastases, are tumors that originatedelsewhere in the body, but have now spread, to a distant tissues andorgans. There are some malignancies that are predisposed to spreading tothe skeleton. Prostrate cancer and breast carcinoma typicallymetastasize to bone. Another frequent site of tumor metastasis is thebrain.

The common routes for tumor metastasis are direct growth into adjacentstructures, spread through the vascular or lymphatic systems, andtracking along tissue planes and body spaces (e.g., peritoneal fluid,cerebrospinal fluid, etc.). Clinically, most patients die frommetastatic disease.

The present invention is not limited to any particular mechanism.Indeed, an understanding of any particular mechanism is unnecessary topractice (make and use) the compositions and methods of the presentinvention. Nonetheless, it is believed that the molecular mechanismsinvolved in metastatic tumor maintenance are different from thoseinvolved in primary tumor maintenance. The present inventioncontemplates that elucidation of the cellular mechanisms associated withmetastatic cancer maintenance and metastasis provides insight into thedevelopment of new effective anticancer treatments.

Malignant tumor progression, in many cases, is correlated with increasedmigratory capacity involving, at least in part, alteredmetalloproteolytic activity. Tumor invasion is thought to rely on themodification of cell adhesion and the proteolysis of extracellularmatrix components. Bcl-2 is though to have specific effects on themolecules involved in cancer cell migration and invasion (See, V.Amberger, et al., Cancer Res., 58:149-158 (1998)). Cancer cells thatexpress Bcl-2 proteins may be more invasive than other cancer cells.Bcl-2 proteins are also thought to enhance cancer cell migration andinvasion by altering the expression of metalloproteinases and theirinhibitors. Wick et al. (W. Wick, et al., FEBS Lett., 440:419-424(1998)) reported that ectopic expression of Bcl-2 in two glioma celllines significantly enhanced migration and invasion in a Matrigel-coatedmembrane invasion assay (See, S. Mohanam, et al., Cancer Res.53:4143-4147 (1993)) and a fetal rat brain confrontation assay (See, P.Pedersen, et al., Cancer Res., 53:5158-5165 (1993)). Bcl-2 expression isalso thought to lead to activation and/or increase of matrixmetalloproteinases (e.g., MMP-2, MMP-9) or the cell surfaceurokinase-type plasminogen activator (u-PA), and reductions ofmetalloproteinases tissue inhibitors (TIMPs).

Successful migration and invasion of cancer cells requires the abilityto survive, or to become resistant to, the endogenous apoptotic deathprogram signals once the cancer cell has detached from the primary tumortissue. The present invention is not limited to any particularmechanism. Indeed, an understanding of any particular mechanism isunnecessary to practice (make and use) the compositions and methods ofthe present invention. Nonetheless, the present invention contemplatesthat overexpression of anti-apoptotic Bcl-2 proteins provides tumorcells with a mechanism for surviving in new and non-permissiveenvironments (e.g., metastatic sites), and contributes to theorganospecific pattern of clinical metastatic cancer spread. It isfurther contemplated that overexpression of Bcl-X_(L) counteracts theproapoptotic signals in the cancer cells' microenvironment, thusfavoring successful development of metastases. The bcl-X_(L) gene isfurther thought to play a role in breast cancer dormancy by promotingthe survival of cells in metastatic foci in specific organs (See, NuriaRubio, Lab Invest, 81:725-734 (2001)). For example, in human breastcarcinomas, the overexpression of anti-apoptotic Bcl-X_(L) protein isthought to increase metastatic potential by providing, at least in part,increased resistance to cytokines, overriding apoptotic signals,enhancing anchorage-independent growth (e.g., caused by a modifiedinteraction with the extracellular matrix), and increasing cell survivalin the circulation (Fernandez et al., Cell Death Differ., 7:350-359(2000)). It has been shown that a number of cell adhesion molecules playa role in metastasis and that integrins are especially involved intumorigenic spread. Integrins are implicated in cell-cell andcell-extracellular matrix (ECM) interactions, signaling, sensingcellular microenvironment, and in moderating cellular activitiesincluding, but not limited to, migration, differentiation, survival andtissue (re)modeling in both normal and pathological states. The presentinvention contemplates that anti-apoptotic proteins such as Bcl-2 and/orBcl-X_(L) regulate cell-cell interactions (See, J. Reed, Nature,387:773-776 (1997)). Down-regulation of cell surface integrins byantibodies could lead to induction of apoptosis. For example, Bcl-2expression is up-regulated by α₅β₁ integrins preventing apoptosis whencells are detached from the matrix (See, S. Frisch and E. Ruoslahti,Curr. Opin. Cell Biol., 9:701-706 ((1997)). Expression of Bcl-2 iscontemplated to promote the metastatic potential of the human breastcancer cell line MCF7 in vivo and migratory and invasive properties invitro (See, D. Del Bufalo, et al., FASEB J., 11:947-953 (1997)).

In some embodiments, the present invention provides methods ofinhibiting tumor metastasis in a subject, comprising administering tothe subject a gossypol compound (e.g., (−)-gossypol) that decreases thesurvival of metastatic cells by inhibiting cellular activity ofBcl-2/Bcl-X_(L) proteins. In certain other embodiments, the presentinvention provides methods of treating (e.g., ameliorating and/orpreventing) cancer metastasis comprising administering to a subjecthaving a cancer metastasis a therapeutically effective amount of agossypol compound (e.g., (−)-gossypol), and optionally one or moreanticancer and/or anti-neoplastic agents. The present invention is notintended to be limited to administering any particular gossypolcompound, or compounds for the prevention (or retarding) of tumormetastasis. Indeed, a number of gossypol compounds are contemplated asbeing useful in the preventing, attenuating, or retarding of tumormetastasis including, but not limited to, (±)-gossypol; (−)-gossypol;(+)-gossypol; (±)-gossypolone; (−)-gossypolone; (+)-gossypolone;(±)-gossypol acetic acid; (−)-gossypol acetic acid; (+)-gossypol aceticacid; (±)-ethyl gossypol; (−)-ethyl gossypol; (+)-ethyl gossypol;(±)-hemigossypolone; (−)-hemigossypolone; (+)-hemigossypolone; Schiff'sbase of (±)-gossypol; Schiff's base of (−)-gossypol; Schiff's base of(+)-gossypol; Schiff's base of (±)-gossypolone; Schiff's base of(−)-gossypolone; Schiff's base of (+)-gossypolone; Schiff's base of(±)-gossypol acetic acid; Schiff's base of (−)-gossypol acetic acid;Schiff's base of (+)-gossypol acetic acid; Schiff's base of (±)-ethylgossypol; Schiff's base of (−)-ethyl gossypol; Schiff's base of(+)-ethyl gossypol; Schiff's base of (±)-hemigossypolone; Schiff's baseof (−)-hemigossypolone; Schiff's base of (+)-hemigossypolone,(±)-apogossypol, (−)-apogossypol, (+)-apogossypol, (t)-apogossypolacetic acid, (−)-apogossypol acetic acid, (+)-apogossypol acetic acid,(±)-ethyl apogossypol, (−)-ethyl apogossypol, (+)-ethyl apogossypol, andthe like. The present invention further contemplates that a range ofadditional (second) chemotherapeutic, anticancer, or anti-neoplasticagents, radiation therapies, and/or surgical interventions canoptionally be combined (in any temporal order) with gossypol compoundsto prevent or retard tumor metastasis in a subject. In this regard, thepresent invention describes various exemplary additional (second) agentsand therapies that are useful in certain embodiments of the presentinvention directed to tumor metastasis.

An important goal in oncology is to optimize the use of availabletreatment options (e.g., chemotherapy, radiation therapy, surgery, andthe like) to achieve maximum obtainable therapeutic effect whilepreserving organs and the subject's general quality of life.

Bcl-2 is the founding member of a family of proteins and was firstisolated as the product of an oncogene. The Bcl-2 family of proteins nowincludes both anti-apoptotic molecules such as Bcl-2 and Bcl-X_(L) andpro-apoptotic molecules such as Bax, Bak, Bid, and Bad. Bcl-2 andBcl-X_(L) are thought to be important regulators of Bcl-2 familymediated apoptosis.

In preferred embodiments, the administration of gossypol compounds iscontemplated to provide an effective treatment of neoplastic conditionsand other disorders that involve either the aberrant hyperproliferationor defective apoptosis of cells (e.g., tumor cells).

In other preferred embodiments, the present invention provides methodsof treatment or prophylaxis of cancers in a subject comprisingadministering to the subject a gossypol compound in an amount effectiveto inhibit Bcl-2 and/or Bcl-X_(L), thus inducing apoptosis andsuppressing tumor growth and/or proliferation. Preferably, a gossypolcompound is administered in conjunction with another agent or treatment,such as a chemotherapeutic agent (e.g., a tumor cell apoptosis promotingagent) or radiation. The present invention is not limited to anyparticular mechanism. Indeed, an understanding of any particularmechanism is unnecessary to practice (make and use) the methods andcompositions of the present invention. Nonetheless, it is contemplatedthat increasing apoptosis in target cells (e.g., pathogenic cellsincluding, but not limited to, cancer cells) reestablishes normalapoptotic control associated with basal expression of Bcl-2 and/orBcl-X_(L) and/or another anti-apoptotic Bcl-2 family protein (e.g.Bcl-w).

The methods of the present invention are particularly well suited forthe treatment of cancers characterized by overexpression of Bcl-2 familyproteins including, but not limited to, Bcl-2 and/or Bcl-X_(L).

In some preferred embodiments, the methods of the present inventionprovide effective amounts of gossypolone to a patient having a conditioncharacterized by the overexpression of Bcl-2 family proteins, andoptionally one or more anticancer or anti-neoplastic agent including,but not limited to radiation therapy.

In one preferred embodiment, the present invention provides a method ofmodulating apoptosis in a cell comprising: providing a cell, wherein thecell overexpresses a Bcl-2 family protein; a gossypol compound; andtreating the cell with an effective amount of the gossypol compoundunder conditions such that apoptosis in the cell is modulated.

The methods of the present invention are not intended to be limited toadministration of any particular gossypol compounds. Indeed, the presentinvention contemplates the administration of a number of gossypolenantiomers, metabolites, derivatives, and pharmaceutically acceptablesalts, as well as Schiff's bases of these compounds. For example,gossypol compounds suitable for use in the present invention include,but are not limited to, (±)-gossypol; (−)-gossypol; (+)-gossypol;(±)-gossypolone; (−)-gossypolone; (+)-gossypolone; (±)-gossypol aceticacid; (−)-gossypol acetic acid; (+)-gossypol acetic acid; (±)-ethylgossypol; (−)-ethyl gossypol; (+)-ethyl gossypol; (±)-hemigossypolone;(−)-hemigossypolone; (+)-hemigossypolone; Schiff's base of (±)-gossypol;Schiff's base of (−)-gossypol; Schiff's base of (+)-gossypol; Schiff'sbase of (±)-gossypolone; Schiff's base of (−)-gossypolone; Schiff's baseof (+)-gossypolone; Schiff's base of (±)-gossypol acetic acid; Schiff'sbase of (−)-gossypol acetic acid; Schiff's base of (+)-gossypol aceticacid; Schiff's base of (±)-ethyl gossypol; Schiff's base of (−)-ethylgossypol; Schiff's base of (+)-ethyl gossypol; Schiff's base of(±)-hemigossypolone; Schiff's base of (−)-hemigossypolone; Schiff's baseof (+)-hemigossypolone, (±)-apogossypol, (−)-apogossypol,(+)-apogossypol, (±)-apogossypol acetic acid, (−)-apogossypol aceticacid, (+)-apogossypol acetic acid, (±)-ethyl apogossypol, (−)-ethylapogossypol, (+)-ethyl apogossypol, and the like.

In preferred embodiments, the present invention provides administeringthe (−)-gossypol enantiomer to a patient having a conditioncharacterized by overexpression of a Bcl-2 family protein. In someembodiments, the overexpressed Bcl-2 family proteins contemplatedinclude, but are not limited to, Bcl-2, Bcl-X_(L), Mcl-1, Bcl-w,A1/BFL-1, BOO-DIVA, Bcl-6, Bcl-8, and Bcl-y. In still some otherembodiments, the overexpressed Bcl-2 family proteins have pro-apoptoticactivity. In yet other embodiments, the overexpressed Bcl-2 familyproteins have anti-apoptotic activity.

In some embodiments, the compositions and methods of the presentinvention are used to treat diseased cells, tissues, organs, orpathological conditions and/or disease states in a subject organism(e.g., a mammalian subject including, but not limited to, humans andveterinary animals), or in in vitro and/or ex vivo cells, tissues, andorgans. In this regard, various diseases and pathologies are amenable totreatment or prophylaxis using the present methods and compositions. Anon-limiting exemplary list of these diseases and conditions includes,but is not limited to, breast cancer, prostate cancer, lymphoma, skincancer, pancreatic cancer, colon cancer, melanoma, malignant melanoma,ovarian cancer, brain cancer, primary brain carcinoma, head-neck cancer,glioma, glioblastoma, liver cancer, bladder cancer, non-small cell lungcancer, head or neck carcinoma, breast carcinoma, ovarian carcinoma,lung carcinoma, small-cell lung carcinoma, Wilms' tumor, cervicalcarcinoma, testicular carcinoma, bladder carcinoma, pancreaticcarcinoma, stomach carcinoma, colon carcinoma, prostatic carcinoma,genitourinary carcinoma, thyroid carcinoma, esophageal carcinoma,myeloma, multiple myeloma, adrenal carcinoma, renal cell carcinoma,endometrial carcinoma, adrenal cortex carcinoma, malignant pancreaticinsulinoma, malignant carcinoid carcinoma, choriocarcinoma, mycosisfungoides, malignant hypercalcemia, cervical hyperplasia, leukemia,acute lymphocytic leukemia, chronic lymphocytic leukemia, acutemyelogenous leukemia, chronic myelogenous leukemia, chronic granulocyticleukemia, acute granulocytic leukemia, hairy cell leukemia,neuroblastoma, rhabdomyosarcoma, Kaposi's sarcoma, polycythemia vera,essential thrombocytosis, Hodgkin's disease, non-Hodgkin's lymphoma,soft-tissue sarcoma, osteogenic sarcoma, primary macroglobulinemia, andretinoblastoma, and the like, T and B cell mediated autoimmune diseases;inflammatory diseases; infections; hyperproliferative diseases; AIDS;degenerative conditions, vascular diseases, and the like. In someembodiments, the cancer cells being treated are metastatic.

In some embodiments, infections suitable for treatment with thecompositions and methods of the present invention include, but are notlimited to, infections caused by viruses, bacteria, fungi, mycoplasma,prions, and the like. The present invention is not intended to belimited, however, to treating of any particular infections or infectiousagents.

In one preferred embodiment, the present invention provides methods ofmodulating cell division in a tissue comprising: providing a tissue,wherein the tissue overexpresses a Bcl-2 protein; a gossypol compound;an anticancer agent; and treating the tissue with effective amounts ofthe gossypol compound and the anticancer agent under conditions suchthat cell division is modulated. In some of these embodiments, thepresent invention contemplates gossypol compounds bind to Bcl-2 familyproteins thus modulating cell division. In still further embodiments,the methods optionally comprise one or more antineoplastic and/oranti-hyperproliferative chemotherapeutic agents (e.g., small or largemolecule drugs, polypeptides, polynucleotides, synthetic or naturallyoccurring chemical compounds, and the like), or therapies (e.g.,radiation therapy, surgical interventions, etc.).

In yet another embodiment, the present invention provides methods oftreating a subject (e.g., a patient) comprising administering a gossypolcompound to a subject overexpressing a Bcl-2 family protein. In apreferred example of these embodiments, the gossypol compound binds to aBcl-2 family protein.

Some embodiments of the present invention are directed to providingmethods of treating a subject comprising administering a gossypolcompound and one or more anticancer agents to a subject overexpressing aBcl-2 family protein.

A number of suitable anticancer agents are contemplated for use in themethods of the present invention. Indeed, the present inventioncontemplates, but is not limited to, administration of numerousanticancer agents such as: agents that induce apoptosis; polynucleotides(e.g., anti-sense, ribozymes, siRNA); polypeptides (e.g., enzymes andantibodies); biological mimetics (e.g., gossypol or BH3 mimetics);agents that bind (e.g., oligomerize or complex) with a Bcl-2 familyprotein such as Bax; alkaloids; alkylating agents; antitumorantibiotics; antimetabolites; hormones; platinum compounds; monoclonalor polyclonal antibodies (e.g., antibodies conjugated with anticancerdrugs, toxins, defensins, etc.), toxins, radionuclides; biologicalresponse modifiers (e.g., interferons (e.g., IFN-α, etc.) andinterleukins (e.g., IL-2, etc.), etc.); adoptive immunotherapy agents;hematopoietic growth factors; agents that induce tumor celldifferentiation (e.g., all-trans-retinoic acid, etc.); gene therapyreagents (e.g., antisense therapy reagents and nucleotides); tumorvaccines; angiogenesis inhibitors; proteosome inhibitors: NF kappa βmodulators; anti-CDK compounds; HDAC inhibitors; and the like. Numerousother examples of chemotherapeutic compounds and anticancer therapiessuitable for co-administration with the disclosed gossypol compounds areknown to those skilled in the art.

In preferred embodiments, anticancer agents comprise agents that induceor stimulate apoptosis. Agents that induce apoptosis include, but arenot limited to, radiation (e.g. X-rays, gamma rays, UV); kinaseinhibitors (e.g., Epidermal Growth Factor Receptor (EGFR) kinaseinhibitor, Vascular Growth Factor Receptor (VGFR) kinase inhibitor,Fibroblast Growth Factor Receptor (FGFR) kinase inhibitor,Platelet-derived Growth Factor Receptor (PDGFR) kinase inhibitor, andBcr-Abl kinase inhibitors such as GLEEVEC); antisense molecules;antibodies (e.g., HERCEPTIN, RITUXAN, ZEVALIN, and AVASTIN);anti-estrogens (e.g. raloxifene and tamoxifen); anti-androgens (e.g.,flutamide, bicalutamide, finasteride, aminoglutethamide, ketoconazole,and corticosteroids); cyclooxygenase 2 (COX-2) inhibitors (e.g.,celecoxib, meloxicam, NS-398, and non-steroidal anti-inflammatory drugs(NSA/Ds)); anti-inflammatory drugs (e.g., butazolidin, DECADRON,DELTASONE, dexamethasone, dexamethasone intensol, DEXONE, HEXADROL,hydroxychloroquine, METICORTEN, ORADEXON, ORASONE, oxyphenbutazone,PEDIAPRED, phenylbutazone, PLAQUENIL, prednisolone, prednisone, PRELONE,and TANDEARIL); and cancer chemotherapeutic drugs (e.g., irinotecan(CAMPTOSAR), CPT-11, fludarabine (FLUDARA), dacarbazine (DTIC),dexamethasone, mitoxantrone, MYLOTARG, VP-16, cisplatin, carboplatin,oxaliplatin, 5-FU, doxorubicin, gemcitabine, bortezomib, gefitinib,bevacizumab, TAXOTERE or TAXOL); cellular signaling molecules; ceramidesand cytokines; and staurosporine, and the like.

In still other embodiments, the compositions and methods of the presentinvention provide gossypol compounds and at least oneanti-hyperproliferative or antineoplastic agent(s) selected fromalkylating agents, antimetabolites, and natural products (e.g., herbsand other plant and/or animal derived compounds).

Alkylating agents suitable for use in the present compositions andmethods include, but are not limited to: 1) nitrogen mustards (e.g.,mechlorethamine, cyclophosphamide, ifosfamide, melphalan (L-sarcolysin);and chlorambucil); 2) ethylenimines and methylmelamines (e.g.,hexamethylmelamine and thiotepa); 3) alkyl sulfonates (e.g., busulfan);4) nitrosoureas (e.g., carmustine (BCNU); lomustine (CCNU); semustine(methyl-CCNU); and streptozocin (streptozotocin)); and 5) triazenes(e.g., dacarbazine (DTIC; dimethyltriazenoimid-azolecarboxamide).

In some embodiments, antimetabolites suitable for use in the presentcompositions and methods include, but are not limited to: 1) folic acidanalogs (e.g., methotrexate (amethopterin)); 2) pyrimidine analogs(e.g., fluorouracil (5-fluorouracil; 5-FU), floxuridine(fluorode-oxyuridine; FudR), and cytarabine (cytosine arabinoside)); and3) purine analogs (e.g., mercaptopurine (6-mercaptopurine; 6-MP),thioguanine (6-thioguanine; TG), and pentostatin (2′-deoxycoformycin)).

In still further embodiments, chemotherapeutic agents suitable for usein the compositions and methods of the present invention include, butare not limited to: 1) vinca alkaloids (e.g., vinblastine (VLB),vincristine); 2) epipodophyllotoxins (e.g., etoposide and teniposide);3) antibiotics (e.g., dactinomycin (actinomycin D), daunorubicin(daunomycin; rubidomycin), doxorubicin, bleomycin, plicamycin(mithramycin), and mitomycin (mitomycin C)); 4) enzymes (e.g.,L-asparaginase); 5) biological response modifiers (e.g.,interferon-alfa); 6) platinum coordinating complexes (e.g., cisplatin(cis-DDP) and carboplatin); 7) anthracenediones (e.g., mitoxantrone); 8)substituted ureas (e.g., hydroxyurea); 9) methylhydrazine derivatives(e.g., procarbazine (N-methylhydrazine; MIH)); 10) adrenocorticalsuppressants (e.g., mitotane (o,p′-DDD) and aminoglutethimide); 11)adrenocorticosteroids (e.g., prednisone); 12) progestins (e.g.,hydroxyprogesterone caproate, medroxyprogesterone acetate, and megestrolacetate); 13) estrogens (e.g., diethylstilbestrol and ethinylestradiol); 14) antiestrogens (e.g., tamoxifen); 15) androgens (e.g.,testosterone propionate and fluoxymesterone); 16) antiandrogens (e.g.,flutamide): and 17) gonadotropin-releasing hormone analogs (e.g.,leuprolide).

In still other embodiments, the present invention provides methods oftreating cancer in a subject comprising administering to a patienthaving a condition characterized by overexpression of a Bcl-2 familyprotein an effective amount of a gossypol compound.

Additional embodiments are directed to methods of treating cancer in asubject comprising administering to a subject having cancer, wherein thecancer is characterized by overexpression of a Bcl-2 family protein, aneffective amount of a gossypol compound and one or more anticanceragents.

Still other methods are directed to treating cancer in a subjectcomprising administering to a patient having cancer, wherein the canceris characterized by resistance to cancer therapies (e.g.,chemoresistant, radiation resistant, hormone resistant, and the like),an effective amount of a gossypol compound.

In some embodiments, the present invention provides methods of treatingcancer in a subject comprising administering to a patient having cancer,wherein the cancer is characterized by overexpression of a Bcl-2 familyprotein, a dose of a gossypol compound sufficient to reduce theoverexpression of the Bcl-2 protein.

In some embodiments of the present invention, methods of treating cancerin a subject comprising administering to a patient having cancer,wherein the cancer is characterized by overexpression of a Bcl-2 familyprotein, a dose of a gossypol compound and one or more anticancer agentssufficient to reduce the overexpression of the Bcl-2 protein aredescribed.

In still some other embodiments, the present invention provides methodsof treating a hyperproliferative disease, wherein the hyperproliferativedisease is characterized by the overexpression of an anti-apoptoticBcl-2 family protein (e.g., Bcl-2 or Bcl-X_(L)), in a subject comprisingadministering to a subject a dose of a gossypol compound sufficient toinhibit the function of the anti-apoptotic Bcl-2 protein and/or toreduce the overexpression of the protein. In some of these embodiments,the methods further comprise administering one or morehyperproliferative and/or anti-neoplastic therapeutic agents to thesubject.

Some other embodiments of the present invention provide pharmaceuticalcompositions comprising: a gossypol compound; and instructions foradministering the gossypol compound to a subject, the subjectcharacterized by overexpression of a Bcl-2 family protein (e.g., ananti-apoptotic Bcl-2 family member protein). Additional embodimentsprovide pharmaceutical compositions comprising: a gossypol compound; oneor more anticancer agents; and instructions for administering thegossypol compound and the one or more anticancer agents to a subject.

Further embodiments of the present invention provide pharmaceuticalcompositions comprising: a gossypol compound; optionally one or moreanticancer agents; and instructions for administering the gossypolcompound to a subject, the subject characterized by resistance to acancer therapy. In preferred embodiments, the instructions included withthese kits meet U.S. Food and Drug Administration rules, regulations,and suggestions for the administration, preparation, and distribution oftherapeutic kits, compounds, and methods. The instructions optionallyalso satisfy the domestic regulations placed on therapeutic kits,compounds, and methods, by countries and jurisdictions other than theU.S.

In yet another embodiment, the present invention provides methods ofscreening a gossypol compound and a test compound comprising: providing:a gossypol compound; a test compound; a first group of cells; andcontacting the first group of cells with the gossypol compound and thetest compound; and observing the effects of contacting the first groupof cells with the gossypol compound and the test compound. In some ofthese embodiments, the present invention further provides the additionalstep of comparing the effects observed in the first cells against asecond group of the cells contacted with the gossypol compound alone, orwith the test compound alone. Effects that may be observed include, butare not limited to, changes in cell proliferation, changes in apoptoticstatus, and changes in the expression of Bcl-2 family proteins (e.g.,Bcl-2 and/or Bcl-X_(L)), and the like. In still other embodiments, thepresent invention further contemplates additional methods for sellingtest compounds screened/identified by the above methods. In some ofthese embodiments, test compounds may be offered for sale by a thirdparty in one or more forms (e.g. a kit, including instructions foradministering the test compound to a patient). The present inventionfurther provides kits comprising a gossypol compound, one or morechemotherapeutic agents, and instructions for administering the gossypolcompound and the chemotherapeutic agents to a subject. In certain ofthese embodiments, the gossypol compound is (−)-gossypol and thechemotherapeutic agent is selected from docetaxel, TAXOL, cisplatin, andcombinations thereof. The present invention is not limited however tokits comprising (−)-gossypol and docetaxel, TAXOL, cisplatin, andcombinations thereof.

The present invention further provides a method of treating orameliorating a hyperproliferative (or neoplastic) disease in a subjectcomprising administering to the subject a therapeutically effective doseof a gossypol compound and one or more second agent selected from achemotherapeutic agent and radiation. In other embodiments, the presentinvention provides a method of treating or ameliorating ahyperproliferative (or neoplastic) disease in a subject comprisingadministering to the subject a therapeutically effective dose of agossypol compound and one or more second agent selected from achemotherapeutic agent and radiation, with the proviso that acombination of (±)-gossypol, heat, and radiation is not administered. Insome embodiments, the one or more second agents comprise anti-neoplasticagents.

In some methods, a gossypol compound and a chemotherapeutic agent and/orradiation are administered simultaneously. In some other embodiments, agossypol compound and a chemotherapeutic agent and/or radiation areadministered sequentially. In still some other embodiments, a gossypolcompound is administered prior to chemotherapeutic agent(s) and/orradiation. In yet other embodiments, a gossypol compound is administeredafter chemotherapeutic agent(s) and/or radiation.

The present invention further provides methods, wherein a gossypolcompound and a chemotherapeutic agent or radiation are administered withdifferent periodicities, different durations, different concentrations,and/or different administration routes.

Additional embodiments provide methods wherein a gossypol compound and achemotherapeutic agent and/or radiation have a synergistic therapeuticeffect in a subject or in vitro or ex vivo cells, tissues, or organs.

In some embodiments, the subject being treated is an animal such as amammal, fish, or bird. In some embodiments, the mammal being treated isa human. In some other embodiments, the mammal being treated islaboratory animal (e.g. rodent (e.g., mouse, rat, gerbil, rabbit),monkey, dog, pig, cat, etc.). In still some other embodiments, themammal is a veterinary animal (e.g., dog, cat, horse, cow, pig, goat,sheep, etc.).

In certain preferred methods, a gossypol compound is provided to asubject in a dose that sensitizes the subject to treatment by one ormore second agents. The present invention provides compositions andmethods directed at therapeutic treatment of resistant diseases (e.g.,cancer). Diseases that are specifically contemplated by the presentinvention include, but are not limited to, chemotherapy resistantdiseases (e.g., cancers) and radiation therapy resistant diseases (e.g.,cancers). In particularly preferred embodiments, the administration ofgossypol compound(s), and optionally one or more chemotherapeutic agents(e.g., anticancer drug) or therapeutic methods (e.g., radiation therapy)sensitizes the disease (e.g., disease cells) to treatment.

In some embodiments, the hyperproliferative (or neoplastic) disease is acancer (e.g., breast cancer, prostate cancer, pancreatic cancer, coloncancer, lung cancer, lymphoma, melanoma, or head-neck cancer). Thepresent invention contemplates treating metastatic cancers.

The present invention further provides compositions (e.g.,pharmaceutical formulations) and methods for treating diseases (e.g.,cancer) the use of which in a subject results in the regression of thedisease. In other embodiments, the use of the compositions and methodsof the present invention in a subject having a disease (e.g., cancer)results in the arrest or stasis of a disease.

The present invention further provides a pharmaceutical composition forthe treatment of tumors characterized in that it comprises a gossypolcompound and an additional therapeutic agent. Similarly, also providedare pharmaceutical compositions comprising a gossypol compound and anadditional therapeutic agent, wherein the pharmaceutical composition isuseful as an anti-tumor therapy.

In certain pharmaceutical compositions the gossypol compound is selectedfrom the group comprising (−)-gossypol, (+)-gossypol, (−)-gossypolone,(+)-gossypolone, (−)-gossypol acetic acid, (+)-gossypol acetic acid,(−)-ethyl gossypol, (+)-ethyl gossypol, (−)-hemigossypolone,(+)-hemigossypolone, a Schiff's base of (−)-gossypol, a Schiff's base of(+)-gossypol, a Schiff's base of (−)-gossypolone, a Schiff's base of(+)-gossypolone, a Schiff's base of (−)-gossypol acetic acid, a Schiff'sbase of (+)-gossypol acetic acid, a Schiff's base of (−)-ethyl gossypol,a Schiff's base of (+)-ethyl gossypol, a Schiff's base of(−)-hemigossypolone, and a Schiff's base of (+)-hemigossypolone,(−)-apogossypol, (+)-apogossypol, (−)-apogossypol acetic acid,(+)-apogossypol acetic acid, (−)-ethyl apogossypol, (+)-ethylapogossypol, or the racemate of any of the above enantiomeric pairs.

In still other pharmaceutical compositions and therapeutic methods thetarget tumor is selected from the group consisting of breast cancer,prostate cancer, lymphoma, skin cancer, pancreatic cancer, colon cancer,melanoma, malignant melanoma, ovarian cancer, brain cancer, primarybrain carcinoma, head-neck cancer, glioma, glioblastoma, liver cancer,bladder cancer, non-small cell lung cancer, head or neck carcinoma,breast carcinoma, ovarian carcinoma, lung carcinoma, small-cell lungcarcinoma, Wilms' tumor, cervical carcinoma, testicular carcinoma,bladder carcinoma, pancreatic carcinoma, stomach carcinoma, coloncarcinoma, prostatic carcinoma, genitourinary carcinoma, thyroidcarcinoma, esophageal carcinoma, myeloma, multiple myeloma, adrenalcarcinoma, renal cell carcinoma, endometrial carcinoma, adrenal cortexcarcinoma, malignant pancreatic insulinoma, malignant carcinoidcarcinoma, choriocarcinoma, mycosis fungoides, malignant hypercalcemia,cervical hyperplasia, leukemia, acute lymphocytic leukemia, chroniclymphocytic leukemia, chronic granulocytic leukemia, acute granulocyticleukemia, acute myelogenous leukemia, chronic myelogenous leukemia,hairy cell leukemia, neuroblastoma, rhabdomyosarcoma, Kaposi's sarcoma,polycythemia vera, essential thrombocytosis, Hodgkin's disease,non-Hodgkin's lymphoma, soft-tissue sarcoma, osteogenic sarcoma, primarymacroglobulinemia, and retinoblastoma.

The present invention further provides pharmaceutical compositions,wherein an additional therapeutic agent (one or more second agents) isselected from the group consisting of agents that induce apoptosis,pro-apoptotic Bcl-2 proteins, polynucleotides, polypeptides,photodynamic compounds, radiodynamic compounds, radionuclides,radioactive elements, gamma ray emitters, beta particle emitters, drugs,biological mimetics, alkaloids, alkylating agents, antibiotics,antimicrobials, antifungals, antimetabolites, hormones, platinumcompounds, monoclonal antibodies, toxins, defensins, interferons,interleukins, adoptive immunotherapy agents, hematopoietic growthfactors, agents that induce tumor cell differentiation, gene therapyreagents, antisense molecules, kinase inhibitors, vascular growth factorreceptor kinase inhibitor, fibroblast growth factor receptor kinaseinhibitor, platelet-derived growth factor receptor kinase inhibitor,GLEEVEC, anti-estrogens, anti-androgens, cyclooxygenase 2 (COX-2)inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs),chemotherapeutic drugs, nucleotide analogue reverse transcriptaseinhibitors, nucleoside analogue reverse transcriptase inhibitors,non-nucleoside reverse transcriptase inhibitors, protease inhibitors,and combinations thereof. In certain embodiments, the additionaltherapeutic agent (or one or more second agent) is selected from thegroup consisting of 3,7,11,15-tetramethyl-2,6,10,14-hexadecatraen-1-ol,a Bcl-2 family protein (e.g., Bax, Bak, Bid, Bad), DNA, RNA, ribozymes,RNAse, siRNAs, enzymes, ¹¹¹In-oxine, ⁵⁹Fe, ⁶⁷Cu, ¹²⁵L ⁹⁹Te, ⁵¹Cr, ³²P,³H, ³⁵S, ¹⁴C, IFN-α, IL-2, all-trans-retinoic acid, EGFR, VGFR, FGFR,PDGFR, STI-571, GLEEVEC, HERCEPTIN, RITUXAN, raloxifene, tamoxifen,flutamide, bicalutamide, finasteride, aminoglutethamide, ketoconazole,corticosteroids, celecoxib, meloxicam, NS-398, irinotecan CPT-11,fludarabine, dacarbazine, dexamethasone, mitoxantrone, MYLOTARG, VP-16,5-FU, cisplatin, carboplatin, gemcitabine, doxorubicin, TAXOTERE, TAXOL,tenofovir disoproxil fumarate, zidovudine, lamivudine, abacavir,zalcitabine, didanosine, stavudine, nevirapine, delavirdine, efavirenz,saquinavir (SQV (HGC)), saquinavir (SQV (SGC)), ritonavir, indinavir,nelfinavir, amprenavir, mechlorethamine, cyclophosphamide, ifosfamide,melphalan, L-sarcolysin, chlorambucil, hexamethylmelamine, thiotepa,busulfan, carmustine, lomustine, semustine, streptozocin, dacarbazine,methotrexate, fluorouracil, floxuridine, cytarabine, mercaptopurine,thioguanine, pentostatin, vinblastine, vincristine, etoposide,teniposide, dactinomycin, daunorubicin, bleomycin, plicamycin,mitomycin, L-asparaginase, hydroxyurea, procarbazine, mitotane,aminoglutethimide, prednisone, hydroxyprogesterone caproate,medroxyprogesterone acetate, megestrol acetate, diethylstilbestrol,ethinyl estradiol, testosterone propionate, fluoxymesterone, flutamide,and leuprolide, and combinations thereof.

In still some other embodiments, the present invention providescompositions and methods for preventing (or attenuating) the onset orspread of a hyperproliferative disease. In some other embodiments, thepresent invention provides compositions and methods for preventing (orattenuating) the onset or spread of a neoplastic disease. In somepreferred embodiments, the present invention provides methods ofpreventing (or attenuating) cancers in a subject comprisingadministering to the subject a gossypol compound (e.g., (−)-gossypol,(−)-gossypol acetic acid, etc.) in an amount effective to inhibit Bcl-2family protein (e.g., Bcl-2 and/or Bcl-X_(L)). In some of theseembodiments, the Bcl-2 family proteins contemplated include, but are notlimited to, Bcl-2, Bcl-X_(L), Mcl-1, Bcl-w, A1/BFL-1, BOO-DIVA, Bcl-6,Bcl-8, and Bcl-y.

Preferably, methods of preventing (or attenuating) hyperproliferativeand/or neoplastic diseases comprise a gossypol compound administered inconjunction with another agent or treatment, such as an anticanceragent, an anti-neoplastic agent (e.g., a tumor cell apoptosis promotingagent), or radiation therapy. The present methods of preventinghyperproliferative and/or neoplastic diseases are not limited to theadministration of any particular gossypol compound. Indeed, the presentinvention contemplates that a number of gossypol compounds can beadministered to a subject to prevent (or attenuate) hyperproliferativeand/or neoplastic diseases including, but not limited to, (±)-gossypol;(−)-gossypol; (+)-gossypol; (±)-gossypolone; (−)-gossypolone;(+)-gossypolone; (±)-gossypol acetic acid; (−)-gossypol acetic acid;(+)-gossypol acetic acid; (±)-ethyl gossypol; (−)-ethyl gossypol;(+)-ethyl gossypol; (O)-hemigossypolone; (−)-hemigossypolone;(+)-hemigossypolone; Schiff's base of (+)-gossypol; Schiff's base of(−)-gossypol; Schiff's base of (+)-gossypol; Schiff's base of(±)-gossypolone; Schiff's base of (−)-gossypolone; Schiff's base of(+)-gossypolone; Schiff's base of (O)-gossypol acetic acid; Schiff'sbase of (−)-gossypol acetic acid; Schiff's base of (+)-gossypol aceticacid; Schiff's base of (±)-ethyl gossypol; Schiff's base of (−)-ethylgossypol; Schiff's base of (+)-ethyl gossypol; Schiff's base of(±)-hemigossypolone; Schiff's base of (−)-hemigossypolone; Schiff's baseof (+)-hemigossypolone, (±)-apogossypol, (−)-apogossypol,(+)-apogossypol, (±)-apogossypol acetic acid, (−)-apogossypol aceticacid, (+)-apogossypol acetic acid, (±)-ethyl apogossypol, (−)-ethylapogossypol, (+)-ethyl apogossypol, and the like.

Similarly, the present compositions and methods of preventing (orattenuating) a hyperproliferative and/or neoplastic disease are notlimited to any particular additional (second) chemotherapeutic,anticancer, or anti-neoplastic agents or therapies. The presentinvention contemplates that any of the exemplary therapeutics describedherein (or referenced herein) may find use in certain embodiments.

Those skilled in the art can determine the amount of attenuation orwhether prevention of a hyperproliferative and/or neoplastic disease hasoccurred upon use of the compositions and methods of the presentinvention in a subject, or in in vitro or ex vivo cells, tissues, andorgans using standard protocols in comparison to nonpathologicalsubjects, cells, tissues, and organs.

Still further embodiments of the present invention provide the use of agossypol compound and an additional therapeutic agent in the manufactureof a medicament for the treatment of a neoplastic and/orhyperproliferative disease.

Other embodiments of the present invention specifically contemplatechemical intermediates, and formulations of compounds (e.g. gossypolcompounds and optionally one or more chemotherapeutic agents) used inmedicaments, in the manufacture of medicaments, kits for theadministration of medicaments, or diagnostic tests and otherapplications related thereto, and other beneficial formulations.

Also provided are uses of the compositions and methods of the presentinvention for the preparation of therapeutics, medicaments, and othertherapeutic applications.

In yet other embodiments, the present invention provides methods andcompositions according to any of the claims or substantially asdescribed in any of the Examples or various embodiments disclosedherein.

Other advantages, benefits, and preferable embodiments of the presentinvention will be apparent to those skilled in the art.

DESCRIPTION OF THE FIGURES

The following figures form part of the specification and are included tofurther demonstrate certain aspects and embodiments of the presentinvention. The present invention is not intended to be limited howeverto the embodiments specifically recited in these figures.

The following figures form part of the specification and are included tofurther demonstrate certain aspects and embodiments of the presentinvention. The present invention is not intended to be limited howeverto the embodiments specifically recited in these figures.

FIG. 1 shows a sequence alignment of Bcl-2 (SEQ ID NO:1) and Bcl-X_(L)(SEQ ID NO:2).

FIG. 2A shows a ribbon representation of the overall Bcl-2 structure incomplex with the Bak BH3 peptide modeled from the structure of Bcl-X_(L)in complex with Bak BH3 peptide. FIG. 2B shows a detailed representationof the BH3 binding site in Bcl-2.

FIG. 3 shows gossypol directly inhibits binding between Bak BH3 peptideand Bcl-2, and between Bak BH3 peptide and Bcl-X_(L) proteins in certainfluorescence polarization (FP) based binding assays.

FIG. 4 shows the results of competitive inhibition assays using racemicgossypol, (−)-gossypol, and (+)-gossypol to directly block bindingbetween Bid 21-residue BH3 peptide and Bcl-2.

FIG. 5 shows the results of a competitive inhibition assay using racemicgossypol, (−)-gossypol, and (+)-gossypol to directly block bindingbetween Bad 25-residue BH3 peptide and Bcl-X_(L).

FIG. 6A shows the results of a FP-based binding assay of racemicgossypolone to Bcl-X_(L) in one embodiment of the present invention.FIG. 6B shows the results of a FP-based binding assay of a ethylSchiff's base of (−)-gossypol to Bcl-X_(L) (time-course) in oneembodiment of the present invention.

FIG. 7 shows the results of several cancer cell lines and one normalcell line that express various levels of Bcl-2 and/or Bcl-X_(L) proteinsin one embodiment of the present invention.

FIGS. 8A and 8B show the results of cell based assays in variousembodiments of the present invention.

FIG. 9 shows the results of cell based assays in various embodiments ofthe present invention.

FIG. 10 shows the results of cell based assays in various embodiments ofthe present invention.

FIGS. 11A and 11B show the results of the interactions between(−)-gossypol and Bcl-X_(L) protein using ¹⁵N Heteronuclear SingleQuantum Coherence Spectroscopy (HSQC) NMR methods in various embodimentsof the present invention. FIG. 11C shows the three-dimensionalstructural representation of (−)-gossypol in complex with Bcl-X_(L)protein based upon NMR experimental data and computational modeling inone embodiment of the present invention. The Bcl-X_(L) protein isrepresented in a ribbon model and the (−)-gossypol is represented in astick model.

FIG. 12 shows the results of cell based assays in one embodiment of thepresent invention.

FIG. 13 shows the results of cell based assays in one embodiment of thepresent invention.

FIG. 14 shows the results of cell based assays in one embodiment of thepresent invention.

FIG. 15 shows the results of in vivo animal xenograft based assays inone embodiment of the present invention.

FIG. 16 shows the results of cell based assays in various embodiments ofthe present invention.

FIGS. 17A and 17B show the results of cell based assays in variousembodiments of the present invention.

FIG. 18 shows the results of in vivo animal xenograft based assays invarious embodiments of the present invention.

FIG. 19 shows the results of in vivo animal xenograft based assays invarious embodiments of the present invention.

FIG. 20 shows the results of in vivo animal xenograft based assays inone embodiment of the present invention.

FIG. 21 shows the results of cell based assays (inhibition of cellgrowth in several head-neck cancer cell lines and three fibroblast celllines) by (−)-gossypol in one embodiment of the present invention.

FIG. 22 show the results of Western blotting analysis of the proteinlevels of Bcl-2, Bcl-X_(L) and Bcl-X_(S) in several head-neck cancercell lines and one fibroblast cell line in various embodiments of thepresent invention.

FIG. 23 show the results of cell growth inhibition by (−)-gossypol in apanel of head-neck cancer cell lines and one fibroblast cell line asdetermined by an MTT assay (right Y-axis) and its relationship with theratio of Bcl-X_(L)/Bcl-X_(S) (left Y-axis) in various embodiments of thepresent invention.

FIGS. 24A-24C show the results of apoptosis induction studies using(−)-gossypol in 6 cell lines as determined by the TUNEL assay (UM-SCC-1,UM-SCC-6, UM-SCC-12, UM-SCC-14A, fibroblast 1 and fibroblast 2) invarious embodiments of the present invention.

FIG. 25 shows the chemical structures of gossypol, gossyplone, Schiff'sbases of gossypol and Schiff's bases of gossypolone, (−)-gossypol and(+)-gossypol in various embodiments of the present invention.

FIG. 26 shows the results of a saturation curve of Bcl-X_(L) protein toBad 25-residue BH3 peptide.

FIG. 27 shows the results of saturation curve of Bcl-2 protein bindingto Bid 21-residue BH3 peptide.

FIGS. 28A and 28B show the results of nuclear magnetic resonance (NMR)based binding assays of (−)-gossypol and (+)-gossypol to Bcl-X_(L),respectively.

FIG. 29 shows the results of cell based assays in various embodiments ofthe present invention.

FIG. 30 shows the results of cell based assays of gossypol,(−)-gossypol, and (+)-gossypol in various embodiments of the presentinvention.

FIG. 31 shows the results of cell based assays in one embodiment of thepresent invention.

FIGS. 32A and 32B shows the results of cell based assays in oneembodiment of the present invention.

FIG. 33 shows the results of cell based colony formation assays in oneembodiment of the present invention.

FIG. 34 shows the results of cell based assays in various embodiments ofthe present invention.

FIGS. 35A and 35B show the results of cell based assays in oneembodiment of the present invention.

FIG. 36 shows the results of in vivo animal xenograft based assays inone embodiment of the present invention.

FIG. 37 shows the results of in vivo animal xenograft based assays inone embodiment of the present invention.

FIG. 38 shows the results of in vivo animal xenograft based assays inone embodiment of the present invention.

FIG. 39 shows the results of cell based assays of the inhibition of cellgrowth in 2 prostate cancer cell lines PC-3 and LnCaP by racemicgossypol, (−)-gossypol, and (+)-gossypol in various embodiments of thepresent invention.

FIG. 40 shows the results of cell based assays in one embodiment of thepresent invention.

FIG. 41 shows the results of Western blotting analysis of several Bcl-2family proteins in one embodiment of the present invention.

FIG. 42 shows the results of cell based assays in one embodiment of thepresent invention.

FIGS. 43A and 43B show the results of in vivo animal xenograft basedassays in various embodiments of the present invention.

FIG. 44 shows the results of cell based assays in one embodiment of thepresent invention.

FIG. 45 describes the competitive binding curve of racemic apogossypolin directly blocking binding between Bad 25-residue BH3 peptide andBcl-2 using an in vitro fluorescence polarization-based assay.

FIG. 46 describes the competitive binding curve of racemic apogossypolin directly blocking the binding between Bad 21-residue BH3 peptide andBcl-X_(L) protein using an in vitro fluorescence polarization-basedassay.

DEFINITIONS

To facilitate an understanding of the present invention, a number ofterms and phrases are defined below.

As used herein, the term “gossypol compound” refers to enantiomers,isomers, derivatives, metabolites, Schiff's bases, combinations withacids or bases, and pharmaceutically acceptable salts of the gossypolmolecule. Accordingly, gossypol compounds include, but are not limitedto, (±)-gossypol; (−)-gossypol; (+)-gossypol; (±)-gossypolone;(−)-gossypolone; (+)-gossypolone; (±)-gossypol acetic acid; (−)-gossypolacetic acid; (+)-gossypol acetic acid; (±)-ethyl gossypol; (−)-ethylgossypol; (+)-ethyl gossypol; (±)-hemigossypolone; (−)-hemigossypolone;(+)-hemigossypolone; Schiff's base of (±)-gossypol; Schiff's base of(−)-gossypol; Schiff's base of (+)-gossypol; Schiff's base of(±)-gossypolone; Schiff's base of (−)-gossypolone; Schiff's base of(+)-gossypolone; Schiff's base of (±)-gossypol acetic acid; Schiff'sbase of (−)-gossypol acetic acid; Schiff's base of (+)-gossypol aceticacid; Schiff's base of (±)-ethyl gossypol; Schiff's base of (−)-ethylgossypol; Schiff's base of (+)-ethyl gossypol; Schiff's base of(±)-hemigossypolone; Schiff's base of (−)-hemigossypolone; Schiff's baseof (+)-hemigossypolone, (t)-apogossypol, (−)-apogossypol,(+)-apogossypol, (±)-apogossypol acetic acid, (−)-apogossypol aceticacid, (+)-apogossypol acetic acid, (±)-ethyl apogossypol, (−)-ethylapogossypol, (+)-ethyl apogossypol. Acids that may be used incombination with gossypol include, but are not limited to, formic acid,acetic acid, propionic acid, and butyric acid. Physiologicallyacceptable salts include, but are not limited to, salts comprisingsodium hydroxide, potassium hydroxide, lithium hydroxide, bariumhydroxide, sodium carbonate, potassium carbonate, sodium acetate,potassium acetate, pyridine, triethylamine, and quinoline.

Gossypol derivatives include any derivatives that are useful in thepresent invention. One of skill in the art is familiar withderivatization techniques. Many gossypol derivatives are knownincluding, but not limited to, the following compounds:

wherein R=methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl,pentyl, hexyl, heptyl, dodecyl, β-methyl phenylalanine ethyl,phenylalanine methyl ester (Razakantoanina et al. Parasitol. Res.,86:665-668 (2000));

wherein R=methyl and R′=hydrogen, methyl (Dao et al. Bioorg. Med. Chem.,11:2001-2006 (2003));

wherein R=methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl,pentyl, hexyl, heptyl, dodecyl, β-methyl phenylalanine ethyl,phenylalanine methyl ester (Dao et al. Eur. J. Med. Chem., 35:805-813(2000));

wherein R=methyl, ethyl, propyl, butyl, pentyl, propenyl, or t-butyl(Deck et al. J. Med. Chem., 34:3301-3305 (1991));

wherein

R=

or

Przybylski et al. J. Mol. Structure, 611(1-3):193-201 (2002);

(A. I. Meyers and J. Jeffrey Willemsen, Chem. Commun., 16:1573-1574(1997));

(R. E. Royer et al., J. Med. Chem., 38:2427-2432 (1995));

(R. E. Royer et al., J. Med. Chem., 29:1799-1801 (1986));

(C. M. Venuti, J. Org. Chem., 46(15):3124-3127 (1981));

wherein R=Me, Bz and R′=Me, H, and Bz;

wherein R=Me, and H, (I. V. Ognyanoc et al., Helv. Chim. Acta,72:353-360 (1989));

(P. C. Meltzer et al., J. Org. Chem., 50(17):3121-3124 (1985));

(R. Adams et al., J. Am. Chem. Soc., 60:2193-2204 (1938)). Otherderivatives of gossypol are disclosed in the following references: LeBlanc et al. Pharmacol. Res., 46:551-555 (2002); Baumgrass et al. J.Biol. Chem., 276:47914-47921 (2001); Shelley et al. Anticancer Drugs,11:209-216 (2000); Sonenberg et al. Contraception, 37:247-255, (1988);Whaley et al. Contraception, 33:605-616 (1986); Dorsett et al. J. Pharm.Sci., 64:1073-1075 (1975); Wu et al. Yao Xue Xue Bao, 24:502-511 (1989);Hoffer et al. Contraception, 37:301-331 (1988); Guo et al. Yao Xue XueBao, 22:597-602 (1987); and Manmade et al. Experientia, 39:1276-1277(1983).

As used herein, the term “gossypol acetic acid” refers to a compositionof gossypol comprising an amount of acetic acid sufficient to detectablystabilize the gossypol composition as compared to gossypol compositionswithout acetic acid. The range of acetic acid in “gossypol acetic acid”compositions is preferably from about 0.01% to 99% (by weight), morepreferably from about 0.1% to 50%, even more preferably from about 0.5%to 20%. In one embodiment, the gossypol acetic acid is a complexconsisting of equimolar quantities of gossypol and acetic acid(Sigma-Aldrich Corp., St. Louis, Mo.).

As used herein, the terms “(−)-gossypol,” or “(−)-gossypolcompound/composition,” refer to an optically active composition ofgossypol wherein the active molecules comprising the composition rotateplane polarized light counterclockwise (e.g., levorotatory molecules) asmeasured by a polarimeter. Preferably, the (−)-gossypol compound has anenantiomeric excess of 1% to 100%. In one embodiment, the (−)-gossypolcompound has an enantiomeric excess of at least 10%, 20%, 30%, 40%, 50%,60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%(−)-gossypol. In one example of a “(−)-gossypol compound”, the specificrotation ([α]_(D)) of the compound is about −350° to about −390°, about−375° to about −390°, or about −385° to about −390°. (See e.g., Dowd,Chirality, 15:486 (2003); Ciesielska et al., Chem. Phys. Lett. 353:69(2992); Freedman et al., Chirality, 15:196 (2003); and Zhou et al.,Kexue Tongbao, 28:1574 (1983)). Methods for resolving racemic gossypolcompounds into substantially purified (+)- or (−)-gossypol are known(See e.g., Zhou et al., Kexue Tongbao, 28:1574 (1983) (wherein:L-phenylalanine methyl ester was mixed with the aldehyde groups ofgossypol to form a Schiff's base with two diastereoisomers which werethen resolved on a normal silica flash chromatography column. Thefiltrate was concentrated, and the residue was purified bychromatography on silica gel eluting with hexanes:EtOAc=3:1 to give twofractions. Acid hydrolysis of the two fractions in 5N HCl:THF (1:5, roomtemperature, overnight) regenerated the individual gossypol enantiomers,respectively. The first fraction with a higher R_(f) value contained(−)-gossypol, and the second fraction with a lower R_(f) value contained(+)-gossypol. The crude gossypol fractions were extracted into etherfrom the residue after removing THF from the reaction mixture. Thegossypol fractions were then purified by chromatography on silica geland eluted with hexanes:EtOAc (3:1 ratio) to give optically puregossypol, with a yield of 30-40% in two steps. The optical rotatorydispersion values for these products were α_(D)=−352° (c=0.65, CHCl₃)for (−)-gossypol, and α_(D)=+341° (c=0.53, CHCl₃)).

As used herein, the term “gossypol Schiff's base(s)” refers to thegossypol compound that results from the reaction of an aldehyde orketone form of gossypol with a primary amine to yield an imine ofgossypol. Examples of primary amines that can be used include, but arenot limited to, branched and unbranched alkylamines (e.g., methylamine,ethylamine, propylamine, isopropylamine, butylamine, t-butylamine),substituted and unsubstituted arylamines (e.g., phenylamine,benzylamine), and amino acids, such as glycine, alanine, leucine,isoleucine, phenylalanine, tyrosine, tryptophan, lysine, arginine,histidine, aspartate, glutamate, asparagine, glutamine, cysteine, andmethionine.

As used herein, the term “Bcl-2 family proteins,” refers to both theanti-apoptotic members of the Bcl-2 family, including, but not limitedto Bcl-2, Bcl-X_(L), Mcl-1, A1/BFL-1, BOO-DIVA, Bcl-w, Bcl-6, Bcl-8 andBcl-y, and the pro-apoptotic members of the Bcl-2 family, including, butnot limited to Bak, Bax, Bad, tbid, Harakiri, Bim, Bmf, and optionallyother proteins with BH3 (Bcl-2 homology 3) binding pockets that areregulated by gossypol compounds.

As used herein, the terms “overexpression of Bcl-2,” or “overexpressionof a Bcl-2 family protein” refer to an elevated level (e.g., aberrant)of mRNAs encoding for a Bcl-2 family protein(s), and/or to elevatedlevels of such Bcl-2 family protein(s) in cells or tissues as comparedto similar normal corresponding nonpathological cells and tissuesexpressing basal levels of mRNAs encoding Bcl-2 family proteins orhaving basal levels of Bcl-2 family proteins. Methods for detecting thelevels of mRNAs encoding Bcl-2 family proteins, or levels of Bcl-2family proteins, in a cell or tissue include, but are not limited to,Western blotting using Bcl-2 family protein antibodies,immunohistochemical methods, and methods of nucleic acid amplificationor direct RNA detection. As important as the absolute levels of Bcl-2family proteins in cells, tissues, or organs are to determining thatthey overexpress Bcl-2 family proteins, so also are the relative levelsof anti-apoptotic Bcl-2 family proteins to other pro-apoptoticsignalling molecules (e.g., pro-apoptotic Bcl-2 family proteins) withinsuch cells, tissues or organs. When the balance of these two are suchthat, were it not for the levels of the anti-apoptotic Bcl-2 familyproteins, the pro-apototic signalling molecules would be sufficient tocause the cells to execute the apoptosis program and die, said cells insuch tissues or organs would be dependent on the anti-apoptotic Bcl-2family proteins for their survival. In such cells, exposure to aninhibiting effective amount of an anti-apoptotic Bcl-2 family proteininhibitor will be sufficient to cause the cells to execute the apoptosisprogram and die. Thus, the term “overexpression of Bcl-2 family protein”also refers to cells in tissues and organs that, due to the relativelevels of pro-apoptotic signals and anti-apoptotic signals, undergoapoptosis in response to inhibiting effective amounts of compounds thatinhibit the function of anti-apoptotic Bcl-2 proteins.

As used herein, the terms “anticancer agent,” “conventional anticanceragent,” or “cancer therapeutic drug” refer to any therapeutic agents(e.g., chemotherapeutic compounds and/or molecular therapeuticcompounds), radiation therapies, or surgical interventions, used in thetreatment of cancer (e.g., in mammals).

As used herein, the terms “drug” and “chemotherapeutic agent” refer topharmacologically active molecules that are used to diagnose, treat, orprevent diseases or pathological conditions in a physiological system(e.g., a subject, or in vivo, in vitro, or ex vivo cells, tissues, andorgans). Drugs act by altering the physiology of a living organism,tissue, cell, or in vitro system to which the drug has beenadministered. It is intended that the terms “drug” and “chemotherapeuticagent” encompass anti-hyperproliferative and antineoplastic compounds aswell as other biologically therapeutic compounds.

As used herein the term “prodrug” refers to a pharmacologically inactivederivative of a parent “drug” molecule that requires biotransformation(e.g., either spontaneous or enzymatic) within the target physiologicalsystem to release, or to convert (e.g., enzymatically, mechanically,electromagnetically, etc.) the “prodrug” into the active “drug.”“Prodrugs” are designed to overcome problems associated with stability,toxicity, lack of specificity, or limited bioavailability. Exemplary“prodrugs” comprise an active “drug” molecule itself and a chemicalmasking group (e.g., a group that reversibly suppresses the activity ofthe “drug”). Some preferred “prodrugs” are variations or derivatives ofcompounds that have groups cleavable under metabolic conditions.Exemplary “prodrugs” become pharmaceutically active in vivo or in vitrowhen they undergo solvolysis under physiological conditions or undergoenzymatic degradation or other biochemical transformation (e.g.,phosphorylation, hydrogenation, dehydrogenation, glycosylation, etc.).Prodrugs often offer advantages of solubility, tissue compatibility, ordelayed release in the mammalian organism. (See e.g., Bundgard, Designof Prodrugs, pp. 7-9, 21-24, Elsevier, Amsterdam (1985); and Silverman,The Organic Chemistry of Drug Design and Drug Action, pp. 352-401,Academic Press, San Diego, Calif. (1992)). Common “prodrugs” includeacid derivatives such as esters prepared by reaction of parent acidswith a suitable alcohol (e.g., a lower alkanol), amides prepared byreaction of the parent acid compound with an amine (e.g., as describedabove), or basic groups reacted to form an acylated base derivative(e.g., a lower alkylamide).

The term “derivative” of a compound, as used herein, refers to achemically modified compound wherein the chemical modification takesplace either at a functional group of the compound, aromatic ring, orcarbon backbone. Such derivatives include esters of alcohol-containingcompounds, esters of carboxy-containing compounds, amides ofamine-containing compounds, amides of carboxy-containing compounds,imines of amino-containing compounds, acetals of aldehyde-containingcompounds, ketals of carbonyl-containing compounds, and the like.

As used herein, the term “pharmaceutically acceptable salt” refers toany salt (e.g., obtained by reaction with an acid or a base) of acompound of the present invention that is physiologically tolerated inthe target subject (e.g., a mammalian subject, and/or in vivo or exvivo, cells, tissues, or organs). “Salts” of the compounds of thepresent invention may be derived from inorganic or organic acids andbases. Examples of acids include, but are not limited to, hydrochloric,hydrobromic, sulfuric, nitric, perchloric, fumaric, maleic, phosphoric,glycolic, lactic, salicylic, succinic, toluene-p-sulfonic, tartaric,acetic, citric, methanesulfonic, ethanesulfonic, formic, benzoic,malonic, sulfonic, naphthalene-2-sulfonic, benzenesulfonic acid, and thelike. Other acids, such as oxalic, while not in themselvespharmaceutically acceptable, may be employed in the preparation of saltsuseful as intermediates in obtaining the compounds of the invention andtheir pharmaceutically acceptable acid addition salts.

Examples of bases include, but are not limited to, alkali metal (e.g.,sodium) hydroxides, alkaline earth metal (e.g., magnesium) hydroxides,ammonia, and compounds of formula NW₄ ⁺, wherein W is C₁₋₄ alkyl, andthe like.

Examples of salts include, but are not limited to: acetate, adipate,alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate,citrate, camphorate, camphorsulfonate, cyclopentanepropionate,digluconate, dodecylsulfate, ethanesulfonate, fumarate, flucoheptanoate,glycerophosphate, hemisulfate, heptanoate, hexanoate, chloride, bromide,iodide, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate,2-naphthalenesulfonate, nicotinate, oxalate, palmoate, pectinate,persulfate, phenylpropionate, picrate, pivalate, propionate, succinate,tartrate, thiocyanate, tosylate, undecanoate, and the like. Otherexamples of salts include anions of the compounds of the presentinvention compounded with a suitable cation such as Na⁺, NH₄ ⁺, and NW₄⁺ (wherein W is a C₁₋₄ alkyl group), and the like. For therapeutic use,salts of the compounds of the present invention are contemplated asbeing pharmaceutically acceptable. However, salts of acids and basesthat are non-pharmaceutically acceptable may also find use, for example,in the preparation or purification of a pharmaceutically acceptablecompound.

An “effective amount” is an amount sufficient to effect beneficial ordesired results. An effective amount can be administered in one or moreadministrations.

As used herein, the term “administration” refers to the act of giving adrug, prodrug, or other agent (e.g., a gossypol compound), ortherapeutic treatment (e.g., radiation therapy) to a physiologicalsystem (e.g., a subject or in vivo, in vitro, or ex vivo cells, tissues,and organs). Exemplary routes of administration to the human body can bethrough the eyes (opthalmic), mouth (oral), skin (transdermal), nose(nasal), lungs (inhalant), oral mucosa (buccal), ear, by injection(e.g., intravenously, subcutaneously, intratumorally, intraperitoneally,etc.) and the like.

“Coadministration” refers to administration of more than one chemicalagent (e.g., a gossypol compound and/or drugs, prodrugs, etc.) ortherapeutic treatment (e.g. radiation therapy) to a physiological system(e.g., a subject or in vivo, in vitro, or ex vivo cells, tissues, andorgans). “Coadministration” of the respective chemical agents (e.g., agossypol compound and/or drugs, prodrugs, etc.) and therapeutictreatments (e.g., radiation therapy) may be concurrent, or in anytemporal order or physical combination.

As used herein, the term “synergistic” refers to an effect obtained whengossypol and a second agent are administered together (e.g., at the sametime or one after the other) that is greater than the additive effect ofgossypol and the second agent when administered individually. Thesynergistic effect allows for lower doses of gossypol and/or the secondagent to be administered or provides greater efficacy at the same doses.The synergistic effect obtained can be at least 10%, at least 20%, atleast 30%, at least 40%, at least 50%, at least 60%, at least 70%, atleast 80%, at least 90%, at least 100%, at least 125%, at least 150%, atleast 175%, at least 200%, at least 250%, at least 300%, at least 350%,at least 400%, or at least 500% more than the additive effect of thegossypol compound and the second agent when administered individually.For example, with respect to the treatment of cancer, the synergisticeffect can be a decrease in the rate of tumor growth, a decrease intumor mass, a decrease in the number of metastases, an increase in timeto tumor progression, or an increase in survival time. As describedherein, gossypol compounds (e.g., (−)-gossypol) and chemotherapeuticagents, when administered individually, often only inhibit tumor cellproliferation rather than cause regression of the tumor mass. Accordingto the present invention, it is possible to cause actual regression oftumor mass by the administration of gossypol compounds (e.g.,(−)-gossypol) and chemotherapeutic agents. The co-administration of agossypol compound and an anticancer agent may allow for the use of lowerdoses of the gossypol compound and/or the anticancer agent such that thecancer is effectively treated while avoiding any substantial toxicity tothe subject.

The term “sensitize,” and grammatical equivalents thereof, refers tomaking, through the administration of a first agent(s) (e.g., a gossypolcompound and optionally a chemotherapeutic agent and/or radiation), asubject, cell, tissue, or organ more susceptible, or more responsive, tothe biological effects (e.g., promotion or retardation of an aspect ofcellular function including, but not limited to, cell growth,proliferation, invasion, angiogenesis, apoptosis) of a second or moreagent. The “sensitizing effect” of a first agent (e.g., a gossypolcompound and optionally a chemotherapeutic agent and/or radiation) on atarget cell, tissue, or organ can be measured as the difference in theintended biological effect (e.g. promotion or retardation of an aspectof cellular function including, but not limited to, cell growth,proliferation, invasion, angiogenesis, apoptosis) observed upon theadministration of a second or more agent with and without administrationof the first agent. In this regard, the second or more agent can beexogenous to the subject, cell, tissue or organ. Further in this regard,the second or more agent can be endogenous to the subject, cell, tissue,or organ.

As used herein, the term “pharmacological properties” refers to anydesirable or favorable biological activities or physicochemicalcharacteristics of an agent (e.g., a gossypol compound) administered toa physiological system.

As used herein, the term “pharmacokinetic properties” refers to theaction of an agent (e.g., a gossypol compound) in a subject, cell,tissue, or organ over a period of time including, but not limited to,the processes of absorption, distribution, localization in tissues,biotransformation, and excretion.

As used herein, the term “bioavailability” refers to any measure of theability of a an agent (e.g., a gossypol compound) to be absorbed into abiological target fluid (e.g. blood, cytoplasm, CNS fluid, and thelike), tissue, organelle or intercellular space after administration toa physiological system (e.g., a subject or in vivo, in vitro, or ex vivocells, tissues, and organs).

As used herein, the term “biodistribution” refers to the location of anagent (e.g., a gossypol compound) in organelles, cells (e.g., in vivo orin vitro), tissues, organs, or organisms, after administration to aphysiological system.

As used herein, the term “dysregulation of the process of cell death”refers to any aberration in the ability of (e.g., predisposition) a cellto undergo cell death via either necrosis or apoptosis. Dysregulation ofcell death is associated with or induced by a variety of conditions,including for example, autoimmune disorders (e.g., systemic lupuserythematosus, rheumatoid arthritis, graft-versus-host disease,myasthenia gravis, Sjögren's syndrome, etc.), chronic inflammatoryconditions (e.g., psoriasis, asthma and Crohn's disease),hyperproliferative disorders (e.g., tumors, B cell lymphomas, T celllymphomas, etc.), viral infections (e.g., herpes, papilloma, HIV), andother conditions such as osteoarthritis and atherosclerosis. It shouldbe noted that when the dysregulation is induced by or associated with aviral infection, the viral infection may or may not be detectable at thetime dysregulation occurs or is observed. That is, viral-induceddysregulation can occur even after the disappearance of symptoms ofviral infection.

A “hyperproliferative disease,” as used herein refers to any conditionin which a localized population of proliferating cells in an animal isnot governed by the usual limitations of normal growth. Examples ofhyperproliferative disorders include tumors, neoplasms, lymphomas andthe like. A neoplasm is said to be benign if it does not undergoinvasion or metastasis and malignant if it does either of these. A“metastatic” cell or tissue means that the cell can invade and destroyneighboring body structures. Hyperplasia is a form of cell proliferationinvolving an increase in cell number in a tissue or organ withoutsignificant alteration in structure or function. Metaplasia is a form ofcontrolled cell growth in which one type of fully differentiated cellsubstitutes for another type of differentiated cell. Metaplasia canoccur in epithelial or connective tissue cells. A typical metaplasiainvolves a somewhat disorderly metaplastic epithelium.

The pathological growth of activated lymphoid cells often results in anautoimmune disorder or a chronic inflammatory condition. As used herein,the term “autoimmune disorder” refers to any condition in which anorganism produces antibodies or immune cells which recognize theorganism's own molecules, cells or tissues. Non-limiting examples ofautoimmune disorders include autoimmune hemolytic anemia, autoimmunehepatitis, Berger's disease or IgA nephropathy, Celiac Sprue, chronicfatigue syndrome, Crohn's disease, dermatomyositis, fibromyalgia, graftversus host disease, Grave's disease, Hashimoto's thyroiditis,idiopathic thrombocytopenia purpura, lichen planus, multiple sclerosis,myasthenia gravis, psoriasis, rheumatic fever, rheumatic arthritis,scleroderma, Sjögren's syndrome, systemic lupus erythematosus, type 1diabetes, ulcerative colitis, vitiligo, and the like.

As used herein, the term “neoplastic disease” refers to any abnormalgrowth of cells or tissues being either benign (non-cancerous) ormalignant (cancerous).

As used herein, the term “anti-neoplastic agent” refers to any compoundthat retards the proliferation, growth, or spread of a targeted (e.g.,malignant) neoplasm.

As used herein, the term “regression” refers to the return of a diseasedsubject, cell, tissue, or organ to a non-pathological, or lesspathological state as compared to basal nonpathogenic exemplary subject,cell, tissue, or organ. For example, regression of a tumor includes areduction of tumor mass as well as complete disappearance of a tumor ortumors.

As used herein, the terms “prevent,” “preventing,” and “prevention”refer to a decrease in the occurrence of hyperproliferative orneoplastic cells in a subject. The prevention may be complete, e.g., thetotal absence of hyperproliferative or neoplastic cells in a subject.The prevention may also be partial, such that the occurrence ofhyperproliferative or neoplastic cells in a subject is less than thatwhich would have occurred without the present invention.

As used herein the term, “in vitro” refers to an artificial environmentand to processes or reactions that occur within an artificialenvironment. In vitro environments can consist of, but are not limitedto, test tubes and cell cultures. The term “in vivo” refers to thenatural environment (e.g., an animal or a cell) and to processes orreactions that occur within a natural environment.

As used herein, the term “host cell” refers to any eukaryotic orprokaryotic cell (e.g., mammalian cells, avian cells, amphibian cells,plant cells, fish cells, and insect cells), whether located in vitro orin vivo.

As used herein, the term “cell culture” refers to any in vitro cultureof cells. Included within this term are continuous cell lines (e.g.,with an immortal phenotype), primary cell cultures, finite cell lines(e.g., non-transformed cells), and any other cell population maintainedin vitro, including oocytes and embryos.

As used herein, the term “subject” refers to organisms to be treated bythe methods of the present invention. Such organisms include, but arenot limited to, humans and veterinary animals (dogs, cats, horses, pigs,cattle, sheep, goats, and the like). In the context of the invention,the term “subject” generally refers to an individual who will receive orwho has received treatment (e.g., administration of gossypolcompound(s), and optionally one or more anticancer agents) for a diseasecharacterized by overexpression of Bcl-2 family proteins (e.g., Bcl-2,Bcl-X_(L), Bcl-w, Mcl-1, A-1(Bfl-1), and Boo).

The term “diagnosed,” as used herein, refers to the recognition of adisease by its signs and symptoms (e.g., resistance to conventionalcancer therapies), or genetic analysis, pathological analysis,histological analysis, and the like.

As used herein, the term “competes for binding” is used in reference toa first molecule (e.g., a gossypol compound) with an activity that bindsto the same target (e.g., Bcl-2 and/or Bcl-X_(L)) as does a secondmolecule (e.g., a pro-apoptotic Bcl-2 family protein, such as Bax, Bak,Bid, and Bad, etc.). The efficiency (e.g., kinetics or thermodynamics)of binding by the first molecule may be the same as, or greater than, orless than, the efficiency of the target binding by the second molecule.For example, the equilibrium binding constant (Kd) for binding to thetarget may be different for the two molecules.

As used herein, the term “antisense” is used in reference to nucleicacid sequences (e.g., RNA, phosphorothioate DNA) that are complementaryto a specific RNA sequence (e.g., mRNA). Included within this definitionare antisense RNA (“asRNA”) molecules involved in gene regulation bybacteria. Antisense RNA may be produced by any method, includingsynthesis by splicing the gene(s) of interest in a reverse orientationto a viral promoter that permits the synthesis of a coding strand. Forexample, once introduced into an embryo, this transcribed strandcombines with natural mRNA produced by the embryo to form duplexes.These duplexes then block either the further transcription of the mRNAor its translation. In this manner, mutant phenotypes may be generated.The term “antisense strand” is used in reference to a nucleic acidstrand that is complementary to the “sense” strand. The designation (−)(i.e., “negative”) is sometimes used in reference to the antisensestrand, with the designation (+) sometimes used in reference to thesense (i.e., “positive”) strand. Regions of nucleic acid sequences thatare accessible to antisense molecules can be determined using availablecomputer analysis methods.

The term “sample” as used herein is used in its broadest sense. A samplesuspected of indicating a condition characterized by the overexpressionof a Bcl-2 family protein may comprise a cell, tissue, or fluids,chromosomes isolated from a cell (e.g., a spread of metaphasechromosomes), genomic DNA (in solution or bound to a solid support suchas for Southern blot analysis), RNA (in solution or bound to a solidsupport such as for Northern blot analysis), cDNA (in solution or boundto a solid support) and the like. A sample suspected of containing aprotein may comprise a cell, a portion of a tissue, an extractcontaining one or more proteins and the like.

The term “test compound” refers to any chemical entity, pharmaceutical,drug, and the like, that can be used to treat or prevent a disease,illness, sickness, or disorder of bodily function, or otherwise alterthe physiological or cellular status of a sample (e.g. the level ofBcl-2 family proteins in a cell). Test compounds comprise both known andpotential therapeutic compounds. A test compound can be determined to betherapeutic by using the screening methods of the present invention. A“known therapeutic compound” refers to a therapeutic compound that hasbeen shown (e.g., through animal trials or prior experience withadministration to humans) to be effective in such treatment orprevention. In preferred embodiments, “test compounds” are anticanceragents. In particularly preferred embodiments, “test compounds” areanticancer agents that induce apoptosis in cells.

As used herein, the term “purified” or “to purify” refers to the removalof undesired components from a sample. As used herein, the term“substantially purified” refers to molecules (e.g., polynucleotides,polypeptides, chemical compounds (e.g., gossypol compounds)) that areremoved from their natural environment, isolated or separated, and areat least 60% free, preferably at least 75% free, and most preferably atleast 90% free from other components with which they are naturallyassociated. For example, an “isolated polynucleotide” is therefore asubstantially purified polynucleotide.

As used herein, the term “genome” refers to the genetic material (e.g.,chromosomes) of an organism or a host cell.

The term “nucleotide sequence of interest” refers to any nucleotidesequence (e.g., RNA or DNA), the manipulation of which may be deemeddesirable for any reason (e.g., treat disease, confer improvedqualities, etc.), by one of ordinary skill in the art. Such nucleotidesequences include, but are not limited to, coding sequences, or portionsthereof, of structural genes (e.g., reporter genes, selection markergenes, oncogenes, drug resistance genes, growth factors, etc.), andnon-coding regulatory sequences which do not encode an mRNA or proteinproduct (e.g., promoter sequence, polyadenylation sequence, terminationsequence, enhancer sequence, etc.).

“Nucleic acid sequence” and “nucleotide sequence” as used herein referto an oligonucleotide or polynucleotide, and fragments or portionsthereof, and to DNA or RNA of genomic or synthetic origin which may besingle- or double-stranded, and represent the sense or antisense strand.As used herein, the terms “nucleic acid molecule encoding,” “DNAsequence encoding,” “DNA encoding,” “RNA sequence encoding,” and “RNAencoding” refer to the order or sequence of deoxyribonucleotides orribonucleotides along a strand of deoxyribonucleic acid or ribonucleicacid. The order of these deoxyribonucleotides or ribonucleotidesdetermines the order of amino acids along the polypeptide (protein)chain translated from the mRNA. The DNA or RNA sequence thus codes forthe amino acid sequence.

The term “gene” refers to a nucleic acid (e.g., DNA or RNA) sequencethat comprises coding sequences necessary for the production of apolypeptide or precursor (e.g., proinsulin). The polypeptide can beencoded by a full length coding sequence or by any portion of the codingsequence so long as the desired activity or functional properties (e.g.,enzymatic activity, ligand binding, signal transduction, etc.) of thefull-length or fragment are retained. The term also encompasses thecoding region of a structural gene and includes sequences locatedadjacent to the coding region on both the 5′ and 3′ ends for a distanceof about 1 kb or more on either end such that the gene corresponds tothe length of the full-length mRNA. The sequences that are located 5′ ofthe coding region and which are present on the mRNA are referred to as5′ untranslated sequences. The sequences that are located 3′ ordownstream of the coding region and which are present on the mRNA arereferred to as 3′ untranslated sequences. The term “gene” encompassesboth cDNA and genomic forms of a gene. A genomic form or clone of a genecontains the coding region interrupted with non-coding sequences termed“introns” or “intervening regions” or “intervening sequences.” Intronsare segments of a gene which are transcribed into nuclear RNA (hnRNA);introns may contain regulatory elements such as enhancers. Introns areremoved or “spliced out” from the nuclear or primary transcript; intronstherefore are absent in the messenger RNA (mRNA) transcript. The mRNAfunctions during translation to specify the sequence or order of aminoacids in a nascent polypeptide.

As used herein, the term “exogenous gene” refers to a gene that is notnaturally present in a host organism or cell, or is artificiallyintroduced into a host organism or cell.

As used herein, the term “vector” refers to any genetic element, such asa plasmid, phage, transposon, cosmid, chromosome, virus, virion, etc.,which is capable of replication when associated with the proper controlelements and which can transfer gene sequences between cells. Thus, theterm includes cloning and expression vehicles, as well as viral vectors.

As used herein, the term “gene expression” refers to the process ofconverting genetic information encoded in a gene into RNA (e.g., mRNA,rRNA, tRNA, or snRNA) through “transcription” of the gene (i.e., via theenzymatic action of an RNA polymerase), and for protein encoding genes,into protein through “translation” of mRNA. Gene expression can beregulated at many stages in the process. “Up-regulation” or “activation”refers to regulation that increases the production of gene expressionproducts (i.e., RNA or protein), while “down-regulation” or “repression”refers to regulation that decreases production. Molecules (e.g.,transcription factors) that are involved in up-regulation ordown-regulation are often called “activators” and “repressors,”respectively.

The terms “homology” and “percent identity” when used in relation tonucleic acids refers to a degree of complementarity. There may bepartial homology (i.e., partial identity) or complete homology (i.e.,complete identity). A partially complementary sequence is one that atleast partially inhibits a completely complementary sequence fromhybridizing to a target nucleic acid sequence and is referred to usingthe functional term “substantially homologous.” The inhibition ofhybridization of the completely complementary sequence to the targetsequence may be examined using a hybridization assay (Southern orNorthern blot, solution hybridization and the like) under conditions oflow stringency. A substantially homologous sequence or probe (i.e., anoligonucleotide which is capable of hybridizing to anotheroligonucleotide of interest) will compete for and inhibit the binding(i.e., the hybridization) of a completely homologous sequence to atarget sequence under conditions of low stringency. This is not to saythat conditions of low stringency are such that non-specific binding ispermitted; low stringency conditions require that the binding of twosequences to one another be a specific (i.e., selective) interaction.The absence of non-specific binding may be tested by the use of a secondtarget which lacks even a partial degree of complementarity (e.g., lessthan about 30% identity); in the absence of non-specific binding theprobe will not hybridize to the second non-complementary target.

When used in reference to a single-stranded nucleic acid sequence, theterm “substantially homologous” refers to any probe that can hybridize(i.e., it is the complement of) the single-stranded nucleic acidsequence under conditions of low stringency as described above. A genemay produce multiple RNA species that are generated by differentialsplicing of the primary RNA transcript. cDNAs that are splice variantsof the same gene will contain regions of sequence identity or completehomology (representing the presence of the same exon or portion of thesame exon on both cDNAs) and regions of complete non-identity (forexample, representing the presence of exon “A” on cDNA 1 wherein cDNA 2contains exon “B” instead). Because the two cDNAs contain regions ofsequence identity they will both hybridize to a probe derived from theentire gene or portions of the gene containing sequences found on bothcDNAs; the two splice variants are therefore substantially homologous tosuch a probe and to each other. The present invention is not limited tothe situation where hybridization takes place only between completelyhomologous sequences. In some embodiments, hybridization takes placewith substantially homologous sequences.

As used herein, the term “protein of interest” refers to a proteinencoded by a nucleic acid of interest.

As used herein, the term “native” (or wild type) when used in referenceto a protein, refers to proteins encoded by partially homologous nucleicacids so that the amino acid sequence of the proteins varies. As usedherein, the term “variant” encompasses proteins encoded by homologousgenes having both conservative and nonconservative amino acidsubstitutions that do not result in a change in protein function, aswell as proteins encoded by homologous genes having amino acidsubstitutions that cause decreased (e.g., null mutations) proteinfunction or increased protein function.

The term “reverse Northern blot” as used herein refers to the analysisof DNA by electrophoresis of DNA on agarose gels to fractionate the DNAon the basis of size followed by transfer of the fractionated DNA fromthe gel to a solid support, such as nitrocellulose or a nylon membrane.The immobilized DNA is then probed with a labeled oligo-ribonucleotideprobe or RNA probe to detect DNA species complementary to the ribo probeused.

As used herein, the term “pathogen” refers to a biological agent thatcauses a disease state (e.g., infection, cancer, etc.) in a host.“Pathogens” include, but are not limited to, viruses, bacteria, archaea,fingi, protozoans, mycoplasma, and parasitic organisms.

As used herein, the term “microorganism” is used to refer to any speciesor type of microorganism, including but not limited to, bacteria,archaea, fungi, protozoans, mycoplasma, and parasitic organisms. As usedherein, the term “fungi” is used in reference to eukaryotic organismssuch as the molds and yeasts, including dimorphic fungi.

As used herein, the term “virus” refers to minute infectious agents,which with certain exceptions, are not observable by light microscopy,lack independent metabolism, and are able to replicate only within aliving host cell. The individual particles (i.e., virions) consist ofnucleic acid and a protein shell or coat; some virions also have a lipidcontaining membrane. The term “virus” encompasses all types of viruses,including animal, plant, phage, and other viruses.

The terms “bacteria” and “bacterium” refer to all prokaryotic organisms,including those within all of the phyla in the kingdom Procaryotae. Itis intended that the term encompass all microorganisms considered to bebacteria including Mycoplasma, Chlamydia, Actinomyces, Streptomyces, andRickettsia. All forms of bacteria are included within this definitionincluding cocci, bacilli, spirochetes, spheroplasts, protoplasts, etc.Also included within this term are prokaryotic organisms which are gramnegative or gram positive. “Gram negative” and “gram positive” refer tostaining patterns with the Gram-staining process which is well known inthe art. (See e.g., Finegold and Martin, Diagnostic Microbiology, 6thEd., C V Mosby St. Louis, pp 13-15 (1982)). “Gram positive bacteria” arebacteria which retain the primary dye used in the Gram stain, causingthe stained cells to appear dark blue to purple under the microscope.“Gram negative bacteria” do not retain the primary dye used in the Gramstain, but are stained by the counterstain. Thus, gram negative bacteriaappear red.

As used herein, the term “antigen binding protein” refers to proteinswhich bind to a specific antigen. “Antigen binding proteins” include,but are not limited to, immunoglobulins, including polyclonal,monoclonal, chimeric, single chain, and humanized antibodies, Fabfragments, F(ab′)2 fragments, and Fab expression libraries. Variousprocedures known in the art are used for the production of polyclonalantibodies. For the production of antibodies, various host animals canbe immunized by injection with the peptide corresponding to the desiredepitope including, but not limited to, rabbits, mice, rats, sheep,goats, etc. In a preferred embodiment, the peptide is conjugated to animmunogenic carrier (e.g., diphtheria toxoid, bovine serum albumin(BSA), or keyhole limpet hemocyanin (KLH)). Various adjuvants are usedto increase the immunological response, depending on the host species,including, but not limited to, Freund's (complete and incomplete),mineral gels such as aluminum hydroxide, surface active substances suchas lysolecithin, pluronic polyols, polyanions, peptides, oil emulsions,keyhole limpet hemocyanins, dinitrophenol, and potentially useful humanadjuvants such as BCG (Bacille Calmette-Guerin) and Corynebacteriumparvum.

For preparation of monoclonal antibodies, any technique that providesfor the production of antibody molecules by continuous cell lines inculture may be used (See e.g., Harlow and Lane, Antibodies: A LaboratoryManual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.).These include, but are not limited to, the hybridoma techniqueoriginally developed by Köhler and Milstein (Köhler and Milstein,Nature, 256:495-497 (1975)), as well as the trioma technique, the humanB-cell hybridoma technique (See e.g., Kozbor et al., Immunol. Today,4:72 (1983)), and the EBV-hybridoma technique to produce humanmonoclonal antibodies (Cole et al., in Monoclonal Antibodies and CancerTherapy, Alan R. Liss, Inc., pp. 77-96 (1985)).

According to the invention, techniques described for the production ofsingle chain antibodies (U.S. Pat. No. 4,946,778; herein incorporated byreference) can be adapted to produce specific single chain antibodies asdesired. An additional embodiment of the invention utilizes thetechniques known in the art for the construction of Fab expressionlibraries (Huse et al., Science, 246:1275-1281 (1989)) to allow rapidand easy identification of monoclonal Fab fragments with the desiredspecificity.

Antibody fragments that contain the idiotype (antigen binding region) ofthe antibody molecule can be generated by known techniques. For example,such fragments include, but are not limited to: the F(ab′)2 fragmentthat can be produced by pepsin digestion of an antibody molecule; theFab′ fragments that can be generated by reducing the disulfide bridgesof an F(ab′)2 fragment, and the Fab fragments that can be generated bytreating an antibody molecule with papain and a reducing agent.

Genes encoding antigen binding proteins can be isolated by methods knownin the art. In the production of antibodies, screening for the desiredantibody can be accomplished by techniques known in the art (e.g.,radioimmunoassay, ELISA (enzyme-linked immunosorbant assay), “sandwich”immunoassays, immunoradiometric assays, gel diffusion precipitinreactions, immunodiffusion assays, in situ immunoassays (using colloidalgold, enzyme or radioisotope labels, for example), Western Blots,precipitation reactions, agglutination assays (e.g., gel agglutinationassays, hemagglutination assays, etc.), complement fixation assays,immunofluorescence assays, protein A assays, and immunoelectrophoresisassays, etc.) etc.

As used herein, the term “instructions for administering said gossypolcompound to a subject” includes instructions for using the compositionscontained in the kit for the treatment of conditions characterized bythe overexpression of a Bcl-2 family protein in a cell or tissue. Theterm also refers to instructions for using the compositions contained inthe kit to treat cancers characterized as being resistant to at leastone conventional anticancer therapy (e.g., chemotherapy). In someembodiments, the instructions further comprise a statement of therecommended or usual dosages of the compositions contained within thekit pursuant to 21 C.F.R. §201 et seq. Additional information concerninglabeling and instruction requirements applicable to the methods andcompositions of the present are available at the Internet web page ofthe U.S.F.D.A.

As used herein, the term “third party” refers to any entity engaged inselling, warehousing, distributing, or offering for sale a compoundcontemplated for co-administration with a gossypol compound for treatingconditions characterized by the overexpression of the Bcl-2 familyproteins.

As used herein, the term “modulate” refers to the activity of a compound(e.g., gossypol compound) to affect (e.g., to promote or retard) anaspect of the cellular function including, but not limited to, cellgrowth, proliferation, invasion, angiogenesis, apoptosis, and the like.

GENERAL DESCRIPTION OF THE INVENTION

Gossypol is a naturally occurring double biphenolic compound derivedfrom crude cotton seed oil (Gossypium sp.). Naturally occurring gossypolexists in two enantiomeric forms, (+) or (−), that when present togethercomprise racemic gossypol. Human trials of racemic gossypol as a malecontraceptive have demonstrated the safety of long term administrationof gossypol. Racemic gossypol is well tolerated in humans.

Gossypol is a known inhibitor of spermatogenesis that may beadministered orally with few side effects. Some researchers have shown,however, that hypokalemia may result from prolonged gossypoladministration. Accordingly, in some embodiments, the present methodsand compositions further comprise the co-administration of potassiumsupplements to patients being treated with gossypol compounds.

Although an understanding of the mechanism is not necessary to practicethe present invention and the present invention is not so limited, thepresent invention contemplates that gossypol is a potent inhibitor ofBcl-2 and Bcl-X_(L) and that the anti-tumor activity of gossypol is due,at least in part, to inhibition of the anti-apoptotic activity of Bcl-2and Bcl-X_(L) and the subsequent induction of apoptosis in cancer cellsexpressing Bcl-2 family proteins. Thus, the present invention providescompositions and methods for targeting subjects characterized asoverexpressing a Bcl-2 family protein. In some of the embodiments, thecancer cells show elevated expression levels of Bcl-2 family proteins ascompared to nonpathological samples (e.g., non-cancerous cells ortissues). In other embodiments, the cancer cells or supporting cellsoperationally manifest elevated expression levels of Bcl-2 familyproteins by virtue of executing the apoptosis program and dying inresponse to an inhibiting effective amount of a gossypol compound (e.g.,(−)-gossypol), said response occurring, at least in part, to thedependence in such cells on anti-apoptotic Bcl-2 family protein functionfor their survival.

In the clinical trials to date, gossypol has shown low toxicity inpatients. In some embodiments, it is contemplated that gossypolcompounds provide efficient single agent treatments for metastaticcancers. The present invention further contemplates that gossypolcompounds represent new classes of anticancer agents that specificallyantagonize the anti-apoptotic effects of Bcl-2 and Bcl-X_(L).

The present invention provides in vivo data that show gossypol compoundssignificantly inhibit tumor growth, but that in some embodimentsgossypol compounds achieve even greater inhibition of tumor growthinhibition when used in combination (co-administration) with one or moreconventional anticancer agents (e.g., docetaxel). Accordingly, inpreferred embodiments, gossypol compounds are administered to patientssuffering from diseases characterized by the overexpression of Bcl-2and/or Bcl-X_(L) (e.g., cancer). Gossypol induces apoptosis in cancercells expressing high levels of Bcl-2 and/or Bcl-X_(L), but gossypol ingeneral has less effect on cells with low levels Bcl-X_(L) and/or Bcl-2expression. In other preferred embodiments, gossypol compounds areadministered with one or more anticancer agents and/or radiation.

Bcl-2 is the founding member of a family of proteins that includes bothanti-apoptotic molecules (e.g., Bcl-2, Bcl-X_(L), Mcl-1, A1/BFL-1,BOO-DIVA, Bcl-w, Bcl-6, Bcl-8, and Bcl-y, and the like) andpro-apoptotic molecules (e.g., Bax, Bak, Bid, and Bad, and the like).The bcl-2 gene is a human proto-oncogene located on chromosome 18. Thebcl-2 gene was discovered as a translocated locus in a B-cell leukemia.This translocation is also found in some B-cell lymphomas. In cancerousB cells, the portion of chromosome 18 containing the bcl-2 locusundergoes a reciprocal translocation with the portion of chromosome 14containing antibody heavy chains. This t(14;18) translocation places thebcl-2 gene close to the heavy chain gene enhancer. The product of thebcl-2 gene, Bcl-2 protein, is an integral membrane protein found in themembranes of the endoplasmic reticulum (ER), nuclear envelope, and theouter membrane of mitochondria. It is contemplated that Bcl-2, andBcl-X_(L), function as crucial antagonists of apoptosis.

Although an understanding of the mechanism is not necessary to practicethe present invention and the present invention is not so limited, it iscontemplated that anti-apoptotic proteins Bcl-2 and Bcl-X_(L) suppressapoptosis by forming heterodimers with pro-apoptotic Bcl-2 familymembers such as Bak, Bad, Bax, Mtd (Bok), Bim, Hrk (DP5), Blk, Bnip3,Bnip3L, and Diva. Additional anti-apoptotic members (or relatedproteins) of the Bcl-2 family are thought to include, but are notlimited to, Mcl-1, A1/BFL-1, BOO-DIVA, Bcl-w, Bcl-6, Bcl-8, and Bcl-y.

Research into the three-dimensional (3D) structures of Bcl-2 andBcl-X_(L) showed that both molecules have a hydrophobic binding pocket(named BH3) that is important to their anti-apoptotic affects. Inparticular, experimental 3D high resolution structures of Bcl-X_(L) (S.W. Muchmore et al., Nature, 381:335-341 (1996); and M. Aritomi et al.,J. Biol. Chem., 272:27886-27892 (1997)) alone and in complex with a BakBH3 (Bcl-2 homology domain 3) peptide (S. Michael et al., Science,275:983-986 (1997)) have been determined. Bcl-2 and Bcl-X_(L) share ahigh degree of homology in their amino acid sequences (45% of identityand 56% of similarity). It has been demonstrated that when there existsa sequence identity of more than 30% between a target protein (Bcl-2)and a template protein (Bcl-X_(L)), current computational homologymodeling methods, such as Modeller (A. Sali et al., Structure, Function,and Genetics, 23:318-326 (1995)) can provide accurate 3D structures ofthe target protein. (See, A. Sali, Curr. Opin. Biotech., 6:437-451(1995)). Therefore, in preferred embodiments of the present invention,computational homology modeling is used to model the 3D structure ofBcl-2 (the target protein) based upon the experimental 3D structuralcoordinates of Bcl-X_(L) (the template protein) before thethree-dimensional experimental Bcl-2 structures were determined.

Fluorescence-polarization based assays showed that gossypol,(−)-gossypol and (+)-gossypol bind to Bcl-2 and Bcl-X_(L) proteins andcompete with pro-apoptotic Bid, Bad, and Bak BH3 peptides. Analysisusing nuclear magnetic resonance (NMR) methods conclusively confirmedthat gossypol, (−)-gossypol, and (+)-gossypol bind to the BH3 bindinggroove in Bcl-X_(L). Thus, gossypol compounds bind to the surface groovein Bcl-2 and Bcl-X_(L) and block the binding of pro-apoptotic proteins(e.g. Bid, Bad and Bak), therefore inhibiting the anti-apoptoticfunctions of Bcl-2 and Bcl-X_(L).

In some embodiments, the present invention provides BH3domain-containing proteins as targets for inhibition. It should beunderstood that where the specification refers to Bcl-2 families ofproteins, the same disclosure pertains to BH3 domain-containingproteins. Thus, in some embodiments, the present invention providescompositions and methods for the regulation of biological conditionsrelated to the aberrant expression of BH3 domain-containing proteins.Likewise, in some other embodiments, the present invention providesmethods and compositions for screening agents and compounds thatmodulate (e.g., inhibit or promote) the aberrant expression of BH3domain-containing proteins.

Bcl-2 and Bcl-X_(L) are highly homologous proteins. Many forms of humancancers (e.g., myeloid leukemia and breast cancer) overexpress Bcl-2,and/or Bcl-X_(L). Both Bcl-2 and Bcl-X_(L) have been found to beoverexpressed in human breast cancers. In particular, Bcl-2 is found tobe overexpressed in 60-80% of human breast cancers. The expression ofBcl-2 is highly correlated with estrogen receptor (ER) positive breastcancer. Bcl-X_(L) is overexpressed in 40-70% of human breast cancers,30-60% of prostate cancers, 80% of B-cell lymphomas, 90% of colorectaladenocarcinomas, and many other forms of cancer. The expression ofBcl-X_(L) is typically correlated with a poor prognosis and shortenedsurvival.

Several lines of evidence indicate that Bcl-2 and Bcl-X_(L) not onlycontribute to cancer progression, but also may confer on cancer cells aresistance to apoptosis induced by conventional anti-cancer therapies.High levels of intracellular Bcl-2 protect cells (e.g., cancer cells)from being destroyed by apoptosis. The majority of solid tumors areprotected by at least one of the anti-apoptotic Bcl-2 proteins. Most ofthe currently available chemotherapeutic cancer agents disrupt cellularDNA integrity or replication, and indirectly trigger apoptosis in tumorcells. Cancers that express high levels of Bcl-2 and/or Bcl-X_(L) areoften resistant to chemotherapeutic agents or radiation therapy.

However, the expression patterns of Bcl-2 and Bcl-X_(L) are different insome cancers that overexpress Bcl-2 family proteins. Several reportssuggest that expression of either Bcl-2 or Bcl-X_(L) proteins issufficient for cancer cells to show Bcl-2 family mediated resistance tochemotherapy or radiation therapy. (See, J. C. Reed, Pharmacology,41:501-553 (1997); J. C. Reed et al., J. Cell Biochem., 6:23-32 (1996)).Additional research suggests that some cancer cells are able to switchfrom overexpression of Bcl-2 to Bcl-X_(L). (See, Z. Han et al., CancerRes., 56:621-628 (1996)). Accordingly, some embodiments of the presentinvention provide administering a therapeutic amount of one or moreBcl-2 antagonists (e.g., small molecules, such as gossypol compounds) topatients having a cancer characterized by overexpression of a Bcl-2family member protein. Similarly, other embodiments of the presentinvention provide administering a therapeutic amount of one or moreBcl-X_(L) antagonists (e.g., small molecules, such as gossypolcompounds) to patients having a cancer characterized by overexpressionof Bcl-X_(L). In still further embodiments, the present inventionprovides methods for administering a combination of two or moreanti-apoptotic Bcl-2 family protein antagonists (e.g. small molecules,such as gossypol compounds) to a patient having a cancer characterizedby the overexpression of anti-apoptotic Bcl-2 family proteins. In someembodiments, a Bcl-2 antagonist and/or a Bcl-X_(L) antagonist areadministered to a subject; optionally, one or more additional anticanceragents may also be administered. The present invention furthercontemplates providing compositions and methods comprising one or moreantagonists to Bcl-2 family protein(s) (e.g., an anti-apoptotic Bcl-2family protein) and one or more additional anticancer agents (e.g.,TAXOL, TAXOTERE, etc.). In preferred embodiments, the present inventioncomprises anticancer methods and compositions comprising providing asubject with a therapeutically effective amount of a gossypol compound,e.g., gossypol, gossypolone, Schiff's bases of gossypol and gossypolone,enantiomers (e.g., (−)-gossypol and (+)-gossypol), and pharmaceuticallyacceptable salts of these compounds.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to naturally occurring and chemicallysynthesized small molecule antagonists of Bcl-2 family proteins. Inparticular, the present invention provides gossypol compounds (e.g.,isomers, enantiomers, racemic compounds, metabolites, derivatives,pharmaceutically acceptable salts, in combination with acids or bases,and the like) and methods of using these compounds as antagonists of theanti-apoptotic effects of Bcl-2 family member proteins (e.g., Bcl-2,Bcl-X_(L), and the like). The present invention also providescompositions comprising gossypol compounds and optionally one or moreadditional therapeutic agents (e.g., chemotherapeutic or anti-neoplasticagents). The present invention also provides methods for treatingdiseases and pathologies (e.g., neoplastic diseases) comprisingadministering a composition comprising gossypol compounds and optionallyone or more additional therapeutic agents (e.g., chemotherapeutic oranti-neoplastic agents) and/or techniques (e.g., radiation therapies,surgical interventions, and the like) to a subject or in vitro cells,tissues, and organs.

Exemplary compositions and methods of the present invention aredescribed in more detail in the following sections: I. Binding activityof Bcl-2 and Bcl-X_(L); II. Structure-based approach for discovery ofsmall molecule inhibitors of Bcl-2 and Bcl-X_(L); III. Characterizationof Bcl-2 family of proteins in cancer cell lines; IV. Gossypol compoundsinhibit cancer cell growth and proliferation; V. Proposed mechanism ofgossypol activity; VI. Activity of gossypol in MDA-231 xenograft micealone and in combination with conventional anticancer agents; VII.Therapeutic agents combined or co-administered with gossypol compounds;VIII. Targeting agents and techniques; IX. Pharmaceutical formulations,administration routes, and dosing considerations, and X. Exemplarycombination therapies.

I. Binding Activity of Bcl-2 and Bcl-X_(L)

Although an understanding of the mechanism is not necessary to practicethe present invention and the present invention is not so limited, it iscontemplated that the anti-apoptotic effects of Bcl-2 and Bcl-X_(L)proteins can be attributed, at least in part, to their ability toheterodimerize with pro-apoptotic Bcl-2 family member proteins such asBak, Bax and Bad. The experimental structures of Bcl-2 and Bcl-X_(L)show that BH1 (Bcl-2 Homology Domain 1), BH2, and BH3 domains of Bcl-2and Bcl-X_(L) form a hydrophobic binding pocket (the BH3 binding pocket)into which the Bak or Bad BH3 domain can bind. (See e.g., S. W. Muchmoreet al., Nature, 381:335-341 (1996); M. Aritomi et al., J. Biol. Chem.,272:27886-27892 (1997); S. Michael et al., Science, 275:983-986 (1997);A. M. Petros et al., Protein Sci., 9:2528-2534 (2000); and A. M. Petroset al., Proc. Natl. Acad. Sci. U.S.A., 98:3012-3017 (2001)). The bindingsite in Bcl-2/Bcl-X_(L) is essential for its anti-apoptotic function.(See e.g., X. M. Yin et al., Nature, 369:321-323 (1994); S. C. Cosulichet al., Curr. Biol., 7:913-920 (1997); S. Michael et al., supra; and A.M. Petros et al., supra).

In preferred embodiments, the present invention provides small moleculesthat bind to Bcl-2 and/or Bcl-X_(L) BH3 binding sites thus blockingtheir hetero-dimerization with pro-apoptotic Bcl-2 family memberproteins (e.g., Bad, Bak, and Bax etc.) such that their anti-apoptoticfunction is antagonized and apoptosis is induced in cells with Bcl-2and/or Bcl-X_(L) overexpression. In some of these embodiments, thepresent invention further provides methods comprising the administrationof one or more additional therapeutic agents (e.g. anticancer agentssuch as TAXOL or TAXOTERE) in combination with the disclosed smallmolecule Bcl-2/Bcl-X_(L) inhibitors (e.g., gossypol compounds).Particularly preferred compositions and methods comprise gossypolcompounds administered in combination with at least one anticancer agent(e.g., TAXOL, TAXOTERE, or cisplatin).

The present invention provides small molecule Bcl-2/Bcl-X_(L) inhibitorsthat have various advantages over other available protein antagonists(e.g., antisense oligonucleotides, antibodies, and peptides). Forexample, various compositions of the present invention have improvedoral availability and lower cost among other advantages.

II. Structure-Based Approach for Discovery of Small Molecule Inhibitorsof Bcl-2 and Bcl-X_(L)

Preferred embodiments of the present invention used a powerfulstructure-based virtual screening methodology to identify small moleculeantagonists of anti-apoptotic Bcl-2 family proteins (e.g., Bcl-2 andBcl-X_(L)) from large 3D chemical databases. The methods took advantageof powerful computational docking programs to identify small organicmolecules that interact with binding sites in the targeted proteins(e.g., the BH3 site in Bcl-2 and/or Bcl-X_(L)).

In one embodiment, the targeted protein, Bcl-X_(L), was screened indocking studies (e.g., using the united-atom approximation) to identifysmall-molecule inhibitors that bind to targeted protein from a libraryof chemicals (e.g., synthetic organic compounds and natural products).For example, in one embodiment, polar hydrogens were added to thetargeted protein, and Kollman united-atom partial charges were assigned.All water molecules were removed. Atomic solvation parameters andfragmental volumes were assigned to the protein atoms using the AutoDockutility, AddSol. (See, AutoDock Web page; G. Morris et al., J. Comp.Chem., 19:1639-1662 (1998)).

In another embodiment, the 3D structure of Bcl-2 was modeled using theMODELLER homology modeling program and methods based upon the 3Dstructure of Bcl-X_(L). (A. Sali et al., Structure, Function, andGenetics, 23:318-326 (1995); and A. Sali, Curr. Opin. Biotech.,6:437-451 (1995)). A BLAST sequence alignment of Bcl-2 (SEQ ID NO:1) andBcl-X_(L) (SEQ ID NO:2) proteins is shown in FIG. 1. In preferredembodiments, this sequence alignment was used in the various homologymodeling experiments of the present invention. Since the Bak BH3 peptidebinds to both Bcl-2 and Bcl-X_(L) with good affinity (See, J. L. Wang etal., Cancer Res., 60:1498-1502 (2000); and J. L. Wang et al., Proc.Natl. Acad. Sci. U.S.A., 97:7124-7129 (2000)), the 3D structure of Bcl-2in complex with the Bak BH3 peptide was modeled based upon theexperimental NMR structure of Bcl-X_(L) complexed with Bak BH3 peptide.(S. Michael et al., Science, 275:983-986 (1997)). The modeled 3D complexstructure was further refined using molecular dynamic (MD) simulationsin explicit water using the CHARMM program (B. R. Brooks et al., J.Comp. Chem., 4, 187-217 (1983); and P. V. R. Schleyer et al., CHARMM:The Energy Function and Its Parameterization with an Overview of theProgram, in The Encyclopedia of Computational Chemistry, 1:271-277 eds.,John Wiley & Sons, Chichester (1998)) with the MSI CHARMM force field.The refined structure of Bcl-2 in complex with Bak BH3 peptide is shownin FIGS. 2A and 2B, respectively. FIG. 2A shows a ribbon representationof the overall Bcl-2 structure complexed with Bak BH3 peptide. FIG. 2Bshows a detailed representation of the BH3 binding site. The carbonatoms in the Bak BH3 peptide are in magenta, while the carbon atoms inthe Bcl-2 protein are in green, the oxygen atoms are in red and thenitrogen atoms are in blue. The potential Bcl-2/Bcl-X_(L) inhibitorswere confirmed using biochemical and biological assays.

In some embodiments, as compared to random screening methods, thestructure-based 3D-database screening methods of the present inventionare more effective and less costly. In one embodiment, athree-dimensional structural database containing approximately 6,000natural products isolated from traditional herbal medicine libraries wasscreened using the DOCK program to identify inhibitors of Bcl-2 and/orBcl-X_(L). In another embodiment, the latest version of the NationalCancer Institute's (NCI) 3D-database of approximately 250,000 organicsynthetic compounds and natural products (G. W. A. Milne et al., J.Chem. Inf. Comput. Sci., 34:1219-1224 (1994)) was screened using theDOCK program (S. Makino and I. D. Kuntz, J. Comput. Chem. 18:1812-1825(1997)) to identify about 250-500 potential small moleculeBcl-2/Bcl-X_(L) inhibitors. Of the 259 compounds initially selected, 141were available from the NCI chemical repository and were thus obtainedfor use in in vitro binding assays.

In one embodiment, further testing of the potential non-peptide smallmolecule inhibitors was done using an established sensitive andquantitative in vitro fluorescence polarization (FP) based bindingassay. (See, I. J. Enyedy et al., J. Med. Chem., 44:313-4324 (2001)).The 141 candidate compounds were screened using the FP bind assay fortheir ability to compete with Bak BH3 peptide in binding to Bcl-2. Fromthe 141 compounds tested, a subset of 20 compounds was found to displayIC₅₀ values ranging from 0.7 μM to 25 μM. Fifteen distinct classes ofchemicals were represented within the 20 compound subset. The IC₅₀ valueof the natural Bak BH3 peptide was 0.3 μM in the FP binding assays. Eachof the 20 small molecules inhibitors identified blocked the binding(complexing) of Bcl-2 and Bak BH3 peptides. Several of the smallmolecule inhibitors also potently induced apoptosis and thus inhibitedthe viability and growth of cancer cells with Bcl-2 overexpression.

Since Bcl-X_(L) and Bcl-2 have similar 3D structures, it was reasonedthat some of the potential Bcl-2 inhibitors would also bind toBcl-X_(L). Accordingly, additional screening efforts were directed atdiscovering potential non-peptide small molecule antagonists ofBcl-X_(L) using the FP based binding assay described above.

Although Bcl-2 and Bcl-X_(L) have similar functions, the two proteinshave different expression patterns in human cancers. Furthermore,although Bcl-2 and Bcl-X_(L) share structurally similar BH3 bindingsites, there are differences between the two. It was discovered thatwhile some small molecule inhibitors of Bcl-2 also have good bindingaffinity for Bcl-X_(L), some other small molecule inhibitors only weaklybound Bcl-X_(L) (although these molecules are still effectiveantagonists in some compositions and methods). Some relatively weakBcl-2 small molecule inhibitors had much higher potency when binding toBcl-X_(L). In particular, it was found that gossypol binds to both Bcl-2and Bcl-X_(L) proteins. FIG. 3 shows direct inhibition of the bindingbetween Bak BH3 peptide and Bcl-2 (Bcl-X_(L)) by gossypol measured usinga FP based binding assay. The non-FP labeled Bak peptide has an IC₅₀value of 0.3 μM to Bcl-X_(L).

In one embodiment, it was found that racemic gossypol binds to Bcl-2 andBcl-X_(L). FIG. 3 shows racemic gossypol directly inhibits bindingbetween Bak BH3 peptide and Bcl-2. FIG. 3 further shows that racemicgossypol directly inhibits binding between Bak BH3 peptide andBcl-X_(L).

In another embodiment, it was found that enantiomers of gossypol (e.g.,(−)-gossypol and (+)-gossypol) bind to Bcl-2 and Bcl-X_(L) proteins.FIG. 4 shows racemic gossypol, (−)-gossypol, and (+)-gossypol directlyinhibit binding between Bid BH3 peptide and Bcl-2. FIG. 5 shows racemicgossypol, (−)-gossypol, and (+)-gossypol directly inhibit bindingbetween Bad BH3 peptide and Bcl-X_(L).

In yet another embodiment, it was found that gossypolone binds to Bcl-2and Bcl-X_(L) proteins. FIG. 6A shows racemic gossypolone directlyinhibits binding between Bak BH3 peptide and Bcl-X_(L). FIG. 6B showscompetitive inhibition by (−)-gossypol ethyl Schiff's base of thebinding of Bak BH3 peptide to Bcl-X_(L) protein.

III. Characterization of Bcl-2 Family of Proteins in Cancer Cell Lines

To better understand the molecular mechanism of small moleculeinhibitors of Bcl-2 and Bcl-X_(L), the expression of Bcl-2 familyproteins was characterized in various breast and other cancer cell linesfrom the National Cancer Institute's anti-cancer drug screening program.The results from 5 representative cancer cell lines (i.e., theMDA-MB-231, T-47D, and MDA-435 breast cancer cell lines, the HL-60leukemia cell line, and the HT-29 colon cancer cell line) and 1 normalfibroblast (WI-38) cell line are shown in FIG. 7. The HL-60 leukemiacell line had the highest level of Bcl-2 expression, MDA-MB-231 andMDA-MB-435 breast cancer cell lines also showed very high levels ofBcl-2. Breast cancer cell lines MDA-MB-231 and T-47D, as well as coloncancer cell line HT-29 showed very high levels of Bcl-X_(L) expression.The normal fibroblast cell line showed low levels of Bcl-2 and Bcl-X_(L)expression.

The Bcl-2 family proteins act as arbiters of programmed cell death. Thebalance between anti-apoptotic molecules (e.g., Bcl-2 and Bcl-X_(L)) andpro-apoptotic molecules (e.g., Bid, Bax, Bak and Bad) plays an importantrole in apoptosis. For this reason, the expression status ofpro-apoptotic proteins Bid, Bax, Bak and Bad in cancer cell linesMDA-MB-231, T-47D, MDA-435, HL-60, and HT-29, and normal fibroblast cellline WI-38 were also determined (FIG. 7). All of the cell lines tested,including the normal fibroblast cell line WI-38, expressed high levelsof Bax and most of the cancer cell lines also expressed high levels ofBak. There is significant variations in the expression levels of Bid andBad between different cell lines. Taken together, all 5 of the cancercell lines showed high levels of both anti-apoptotic and pro-apoptoticBcl-2 family proteins, while the normal fibroblast cell line (WI-38)showed only low levels of Bcl-2 and Bcl-X_(L), but high levels ofpro-apoptotic Bcl-2 family members proteins Bax and Bad.

Several other breast cancer cell lines used by the National CancerInstitute (NCI) in their anticancer drug screening efforts were alsotested. These cell lines include BT-549, HS 578T, MCF-7 andNCI/ADR-Resistant. Of these, MCF-7 and BT-549 showed high levels ofBcl-2 protein expression. BT-549 also showed a high level of Bcl-X_(L)protein expression. The cell lines HS 578T and NCI/ADR-RES had mediumlevels of Bcl-X_(L) protein. Thus, among the 7 human breast cancer celllines examined (i.e., MDA-MB-231, T-47D, MDA-435, BT-549, HS 578T,MCF-7, and NCI/ADR-Resistant) 5 of the cell lines had high levels ofeither, or both, Bcl-2 and Bcl-X_(L) expression. Two breast cancer celllines had medium levels of Bcl-2 or Bcl-X_(L) expression. None of the 7breast cancer cell lines tested had low expression of Bcl-2 andBcl-X_(L).

IV. Gossypol Compounds Inhibit Cancer Cell Growth and Proliferation

The fluorescence polarization assays showed that gossypol antagonizesthe binding of Bak, Bid, or Bad BH3 peptide to Bcl-2 and Bcl-X_(L).Thus, the present invention contemplates that small molecule inhibitors(e.g., gossypol compounds) that bind to the BH3 binding domain in Bcl-2and/or Bcl-X_(L) will block the anti-apoptotic functions of theseproteins, and in turn induce apoptosis in cells (e.g., cancer cells)with elevated Bcl-2 and/or Bcl-X_(L) expression. It is furthercontemplated that small molecule inhibitors (e.g., gossypol compounds)also decrease cellular viability and proliferation in cells (e.g.,cancer cells) with high Bcl-2 and/or Bcl-X_(L) expression. Gossypolinhibits cell proliferation (and growth) in cancer, and moreparticularly, in human breast cancers (e.g., MDA-MB-231 cells). Asdescribed herein, the MDA-MB-231 breast cancer cell line has high levelsof expression of both Bcl-2 and Bcl-X_(L).

Various cancer cell inhibition studies were performed with gossypolcompounds. For example, the ability of gossypol compounds to inhibitMDA-MB-231 cell growth was tested in a 5 day MTT assay. Gossypol wasshown to inhibit MDA-MB-231 cell growth with an IC₅₀ value of 2.0 μM.The results in MB-231 and WI-38 cells treated with 20 μM of gossypol for24 hours as detected by the Hoechst Dye assay are shown in FIGS. 8A and8B, respectively. Treatment of MDA-MB-231 cancer cells with gossypolinduces apoptosis. FIG. 8A shows the induction of apoptosis in theMDA-231 cells. Gossypol did not induce normal WI-38 fibroblast cells toundergo apoptosis. FIG. 8B shows that gossypol treatment did not induceapoptosis in normal WI-38 fibroblast cells having low levels (e.g.,basal levels) of Bcl-2 and Bcl-X_(L) expression.

In other tests, gossypol was shown to induce apoptosis in T-47D breastcancer cells having high levels of Bcl-X_(L) expression, but low levelsof Bcl-2 expression. It was also found that gossypol induces apoptosisin other cancer cell lines with high Bcl-X_(L) expression such as HT-29,a human colon cancer cell line, but not in cancer cell lines with lowlevels of Bcl-2 and Bcl-X_(L) expression such as DU-145, a prostatecancer cell line.

Further tests using Annexin-V flow cytometry (FACS) assays wereconducted to more quantitatively assess the ability of gossypol toinduce apoptosis in MDA-MB-231 breast cancer cells. For example, FIG. 9shows gossypol induced apoptosis in human MDA-MB-231 breast cancer cellstreated with gossypol for 24 hours detected using Annexin-V flowcytometry. It was observed that 5.0 μM of gossypol induced 59% of theMDA-MB-231 cells to undergo apoptosis. While the present invention isnot limited to a particular mechanism(s), it is contemplated thatinduction of apoptosis by gossypol is dose-dependent. At administrationsof 10.0 and 20.0 μM, respectively, gossypol induced 74% and 96% ofcancer cells, again respectively, to undergo apoptosis. MDA-MB-231 cellsoverexpress Bcl-2 and Bcl-X_(L).

Since gossypol (e.g., racemic gossypol, (−)-gossypol and (+)-gossypol)is a potent inhibitor of Bcl-X_(L), the present invention contemplatesthat in certain embodiments, gossypol induces apoptosis in cancer cellswith high levels of Bcl-X_(L) expression but low levels of Bcl-2.Indeed, gossypol induces dose-dependent apoptosis in human T-47D breastcancer cells, which as shown above, have high levels of Bcl-X_(L) butlow levels of Bcl-2. FIG. 10 shows the dose dependent induction ofapoptosis in human TD-47 cancer cells treated with gossypol for 24 hoursas detected using Annexin-V flow cytometry.

Since gossypol (e.g. racemic gossypol, (−)-gossypol and (+)-gossypol) isalso a potent inhibitor of Bcl-2, the present invention contemplatesthat in certain embodiments, gossypol induces apoptosis in cancer cellswith high expression levels of Bcl-2 expression but low levels ofBcl-X_(L). Since gossypol binds to both Bcl-2 and Bcl-X_(L) proteins,the present invention contemplates that, in certain embodiments,gossypol induces apoptosis in cancer cells with high levels of Bcl-2 andBcl-X_(L) expression.

These tests show that gossypol is a potent inhibitor of Bcl-X_(L) andinduces cancer cells expressing high levels (e.g., overexpression ascompared to a basal expression rate for a normal example of the celltype) of Bcl-X_(L) to undergo apoptosis, but does not induce apoptosisin cells with normal levels of Bcl-2 and Bcl-X_(L) expression (e.g.,WI-38 cells).

Preferred embodiments of the present invention provide methods ofadministering one or more gossypol compounds to a subject having acondition characterized by the overexpression of Bcl-2 family proteins.The gossypol compounds contemplated for use in the present inventivemethods include, but are not limited to, (±)-gossypol; (−)-gossypol(Super G); (+)-gossypol; (±)-gossypolone; (−)-gossypolone;(+)-gossypolone; (±)-gossypol acetic acid; (−)-gossypol acetic acid;(+)-gossypol acetic acid; (±)-ethyl gossypol; (−)-ethyl gossypol;(+)-ethyl gossypol; (±)-hemigossypolone; (−)-hemigossypolone;(+)-hemigossypolone; Schiff's base of (±)-gossypol; Schiff's base of(−)-gossypol; Schiff's base of (+)-gossypol; Schiff's base of(O)-gossypolone; Schiff's base of (−)-gossypolone; Schiff's base of(+)-gossypolone; Schiff's base of (±)-gossypol acetic acid; Schiff'sbase of (−)-gossypol acetic acid; Schiff's base of (+)-gossypol aceticacid; Schiff's base of (±)-ethyl gossypol; Schiff's base of (−)-ethylgossypol; Schiff's base of (+)-ethyl gossypol; Schiff's base of(±)-hemigossypolone; Schiff's base of (−)-hemigossypolone; Schiff's baseof (+)-hemigossypolone, (±)-apogossypol, (−)-apogossypol,(+)-apogossypol, (±)-apogossypol acetic acid, (−)-apogossypol aceticacid, (+)-apogossypol acetic acid, (±)-ethyl apogossypol, (−)-ethylapogossypol, (+)-ethyl apogossypol as well as derivatives, metabolites,isomers, acids, and pharmaceutically acceptable salts thereof.

In particularly, preferred embodiments, the (−)-gossypol enantiomer(including derivatives, metabolites, acids, Schiff's bases andpharmaceutically acceptable salts thereof) are administered to a subjector to in vitro cells, tissues, or organs.

NMR analysis of the binding of the (−)-gossypol enantiomer shows thatthe (−)-gossypol specifically binds to the BH3 binding groove inBcl-X_(L) (See, FIGS. 11A and 11B). FIG. 12 shows data from growthinhibition experiments comparing (−)-gossypol and (+)-gossypolenantiomers and racemic gossypol in the MDA-MB-231 (2-LMP) breast cancercell line using a 5-day MTT assay.

Additional experiments showed that the T_(1/2) of elimination of(+)-gossypol enantiomer in humans is 29 times that of (−)-gossypol. Insome embodiments, the present invention contemplates that the longerresidency of the (+)-gossypol enantiomer is potentially beneficial incertain prolonged gossypol treatments methods. Therefore, in someembodiments, the (+)-gossypol enantiomer is potentially more toxic tocells. In still some embodiments, the present invention contemplatesthat the longer residency of the (+)-gossypol enantiomer is potentiallybeneficial in certain prolonged gossypol treatments methods.

In other embodiments, (−)-gossypol is administered to patients having acondition characterized by the overexpression of a Bcl-2 family protein.Table 1 compares the inhibition of cell growth in a number of head-neckcancer cell lines treated with (−)-gossypol and cisplatin (CTTP) (astandard agent for the treatment head-neck cancers). Briefly, Table 1compares the inhibition of cell growth demonstrated by (−)-gossypol andcisplatin in a panel of human head-neck cancer cells and the expressionstatus of Bcl-2 family proteins (Bcl-2, Bcl-X_(L) and Bcl-X_(S)). TheIC₅₀ value is the concentration of the drug (e.g., (−)-gossypol andcisplatin) required to inhibit the cell growth by 50% as compared tocontrol cells.

TABLE 1 (−)-gossypol Cisplatin (IC₅₀, μM) Bcl-X_(L) Bcl-X_(S) Bcl-2(IC₅₀, μM) UM-SCC-23 1.5 +++ + − 25 UM-SCC-1 1.5 +++ + − 30 UM-SCC-6 11+++ +++ − >50 UM-SCC-22A 3 ++ + − 5 UM-SCC-12 4 ++ + − 22 UM-SCC-81B 4++ − − 22 UM-SCC-17B 5 ++ + ++ 13 UM-SCC-14A 11 + +++ − 29 UM-SCC-74B 4− + ++ 12 UM-SCC-25 8 + − − 43 Fib-1 20 − − − >50 Fib-2 20 − − − >50Fib-3 18 − − − >50

V. Proposed Mechanism of Gossypol Activity

Although an understanding of any particular proposed mechanism is notnecessary to make and use the compositions and methods of the presentinvention and the present invention is not limited to any particularmechanism(s), it is contemplated that one of the key molecules in theBcl-2/Bcl-X_(L) mediated apoptosis pathway is cytochrome-c (Cyt-c). Itis further contemplated that one of the key functions of Bcl-2/Bcl-X_(L)is to heterodimerize with Bax, Bak, or Bad and to block release of Cyt-cfrom mitochondria. Thus, the ability of gossypol to induce Cyt-c releasefrom mitochondria to the cytosol in cancer cells was tested. Breastcancer cell lines MDA-231 and T47D were treated with either 5 or 20 μMof gossypol for 24 hours. FIG. 13 shows that Cyt-c was released frommitochondria into the cytosol after treatment with 20 μM of gossypol inboth the MDA-231 and T47D breast cancer cell lines (HM, Cyt-c found inthe heavy membrane; Cytosol, Cyt-c found in the cytosol).

It is also contemplated that Bcl-2 mediated apoptosis involves caspase(e.g. caspase-3 and -9) activation once Cyt-c is released from themitochondria. Therefore, tests were conducted to determine whethergossypol activates caspase-3. In one embodiment, the amount of caspase-3cleavage in lysates of MDA-231 breast cancer cells was measured after 12or 24 hours following treatment with gossypol. FIG. 14 shows thatcaspase-3 was cleaved after treatment with gossypol into 17 and 21 kDfragments in a dose dependent manner. Similar results were obtained inT-47D human breast cancer cells and HT-29 colon cancer cells treatedwith gossypol, both of which have high levels of Bcl-X_(L) expressionand relatively low levels of Bcl-2 expression following treatment withgossypol.

In contrast, treatment of human DU-145 prostate cancer cells, having lowBcl-2 and Bcl-X_(L) expression, with 5, 10, or 20 μM of gossypol for 24hours had no effect on caspase-3 activation. Therefore, activation ofcaspase-3 by gossypol is specific and correlative to expression levelsof Bcl-2 and Bcl-X_(L) in cancer cells.

VI. Activity of Gossypol in MDA-231 Xenograft Mice Alone and inCombination with Conventional Anticancer Agents

The potential of gossypol compounds as anticancer therapeutics wasfurther evaluated in MDA-231 xenograft mice. A gossypol treatment regimewas started at day 7 after tumors had grown to 8-10 mm in diameter. Eachtreatment group had five mice bearing two tumors each (one tumor on eachside). A control group of five mice received no gossypol. In the treatedmice, gossypol was administered daily in two different oral doses, a 30and a 90 mg/kg dose, for three weeks. It was found that at both 30 and90 mg/kg daily doses, there is more than 70% inhibition of tumor growthby gossypol with more than a 95% confidence level at day 29. No weightloss or deaths were seen in the mice treated with gossypol. There didnot appear to be any significant difference in the anticancer activityof gossypol in the 30 mg/kg and 90 mg/kg doses. These results suggestthat a 30 mg/kg daily dose of gossypol successfully inhibits tumorgrowth without supplementing the gossypol therapy with adjuvants oradditional anticancer compounds or therapies.

Overexpression of Bcl-2 and/or Bcl-X_(L) proteins appears to protectcancer cells from apoptosis induced by some conventional anticancertherapies (e.g., docetaxel). Some embodiments of the present invention,therefore, provide methods for administering an effective dose(s) ofgossypol (and enantiomers, derivatives, acids (e.g., acetic acid) andpharmaceutically acceptable salts thereof) in combination with at leastone conventional anticancer therapy (e.g., chemotherapeutic agents, suchas docetaxel and/or radiation therapy). In preferred embodiments,gossypol is administered in combination with one or more conventionalanticancer therapies to treat diseases (e.g., cancer) characterized byoverexpression of Bcl-2 family proteins (e.g., Bcl-2 and/or Bcl-X_(L)).In one embodiment of the present invention, when gossypol isadministered, it is not co-administered with radiation and heat.

Although an understanding of any mechanism is not necessary to practicethe present invention and the present invention is not so limited, it iscontemplated that administration of at least one gossypol compoundsensitizes cancer cells having high levels of expression of Bcl-2 familyproteins (e.g., Bcl-2 and/or Bcl-X_(L)) which are resistant toconventional anticancer therapies, to treatment with additionalanticancer agents (e.g., docetaxel). The present invention is, however,not limited to the administration of any particular combination ofgossypol compounds and anticancer therapeutic agents, nor is theinvention limited to any particular sequence or level of agents beingadministered.

In one embodiment of the present invention, the co-administration of agossypol compound and one or more anticancer agents produces asynergistic effect, i.e., an effect that is more than the additiveeffect of each compound administered individually. In a furtherembodiment of the present invention, the co-administration of a gossypolcompound and one or more anticancer agents allows lower doses of thegossypol compound and/or the one or more anticancer agents to be used.The ability to achieve efficacy using lower doses allows theadministration of doses that do not induce any substantial toxicity inthe subject. In another embodiment of the present invention, theco-administration of a gossypol compound and one or more anticanceragents may lead to complete regression of a tumor whereas eithercompound alone would provide only a partial regression. In a furtherembodiment of the present invention, the administration of a gossypolcompound sensitizes neoplastic cells to the therapeutic effect ofanticancer agents. Thus, a lower dose of the anticancer agent issufficient to kill the neoplastic cells when co-administered with agossypol compound.

Examples of lower dose ranges of gossypol compounds and some anticanceragents that can be used in combination with gossypol compounds for thetreatment of particular cancers are presented in Tables 2-4 below. Theseexamples are not intended to limit the present invention in any way.

TABLE 2 Racemic Gossypol Cisplatin Docetaxel Radiation Breast 1-200mg/d; 5-30 mg/m² 10-40 mg/m² 2-65 Gy total Cancer 1, 5, 10, 15, 20,every wk; every wk; dose; 25, 30, 35, 40, 5, 10, 15, 20, 25, 10, 15, 20,25, 2, 5, 10, 15, 20, 45, 50, 55, 60, 30 mg/m² every 30, 35, 40 mg/m²25, 30, 35, 40, 65, 70, 75, 80, wk; every wk; 45, 50, 55, 60, 65 85, 90,95, 100, 5-120 mg/m² 10-60 mg/m² Gy total dose 105, 110, 115, every 3wk; every 2 wk; 120, 125, 130, 5, 10, 15, 20, 25, 10, 15, 20, 25, 135,140, 145, 30, 35, 40, 45, 30, 35, 40, 45, 150, 155, 160, 50, 55, 60, 65,50, 55, 60 mg/m² 165, 170, 175, 70, 75, 80, 85, every 2 wk; 180, 185,190, 90, 95, 100, 105, 20-100 mg/m² 195, 200 mg/d; 110, 115, 120 mg/m²every 3 wk; 40-400 mg every every 3 wk 20, 25, 30, 35, wk; 40, 45, 50,55, 40-400 mg every 60, 65, 70, 75, wk; 80, 85, 90, 95, 40, 50, 60, 70,100 mg/m² every 80, 90, 100, 120, 3 wk 140, 160, 180, 200, 220, 240,260, 280, 300, 320, 340, 360, 380, 400 mg every week Prostate 1-200mg/d; 5-20 mg/m²/d for 5-35 mg/m²/d for 2-78 Gy total Cancer 1, 5, 10,15, 20, 3 d; 2 d; dose; 25, 30, 35, 40, 5, 10, 15, 20 mg/m²/d 5, 10, 15,20, 25, 2, 5, 10, 15, 20, 45, 50, 55, 60, for 3 d; 30, 35 mg/m²/d 25,30, 35, 40, 65, 70, 75, 80, 5-20 mg/m² for 2 d; 45, 50, 55, 60, 85, 90,95, 100, every other d; 5, 10, 15, 20, 25 mg/m^(2/)d 65, 70, 75, 78 Gy105, 110, 115, 5, 10, 15, 20 mg/m² for 4 d total dose 120, 125, 130,every 135, 140, 145, other d; 150, 155, 160, 10-70 mg/m² 165, 170, 175,every 4 wk; 180, 185, 190, 10, 15, 20, 25, 195, 200 mg/d; 30, 35, 40,45, 40-400 mg every 50, 55, 60, 65, 70 mg/m² wk; every 4 wk 40-400 mgevery wk; 40-400 mg every wk; 40, 50, 60, 70, 80, 90, 100, 120, 140,160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400 mg everyweek Colon 1-200 mg/d; 5-30 mg/m²/d for 10-185 mg/m² 2-60 Gy totalCancer 1, 5, 10, 15, 20, 3 d; every 3 wk; dose; 25, 30, 35, 40, 5, 10,15, 20, 25, 10, 15, 25, 35, 2, 5, 10, 15, 20, 45, 50, 55, 60, 30 mg/m²/dfor 45, 55, 65, 75, 25, 30, 35, 40, 65, 70, 75, 80, 3 d 85, 95, 105,115, 45, 50, 55, 60 Gy 85, 90, 95, 100, 125, 135, 145,, total dose 105,110, 115, 155, 165, 175, 120, 125, 130, 185 mg/m² every 135, 140, 145, 3wk 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200 mg/d; 40-400 mgevery wk; 40-400 mg every wk; 40-400 mg every wk; 40, 50, 60, 70, 80,90, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340,360, 380, 400 mg every week Pancreatic 1-200 mg/d; 25-50 mg/m² 5-35mg/m² 2-65 Gy total Cancer 1, 5, 10, 15, 20, every wk; every wk; dose;25, 30, 35, 40, 25, 30, 35, 40, 5, 10, 15, 20, 25, 2, 5, 10, 15, 20, 45,50, 55, 60, 45, 50 mg/m² 30, 35 mg/m² 25, 30, 35, 40, 65, 70, 75, 80,every wk; every wk; 45, 50, 55, 60, 65 85, 90, 95, 100, 5-15 mg/m² 6-100mg/m² Gy total dose 105, 110, 115, every 3 wk; every 3 wk; 120, 125,130, 5, 10, 15 mg/m² 6, 10, 15, 20, 25, 135, 140, 145, every 3 wk; 30,35, 40, 45, 150, 155, 160, 10-100 mg/m² 50, 55, 60, 65, 165, 170, 175,every 4 wk; 70, 75, 80, 85, 180, 185, 190, 10, 15, 20, 25, 90, 95, 100mg/m² 195, 200 mg/d; 30, 35, 40, 45, every 3 wk; 40-400 mg every 50, 55,60, 65, 6-60 mg/m² wk; 70, 75, 80, 85, every 4 wk; 40-400 mg every 90,95, 100 mg/m² 6, 10, 15, 20, 25, wk; every 4 wk 30, 35, 40, 45, 40-400mg every 50, 55, 60 mg/m² wk; every 4 wk 40, 50, 60, 70, 80, 90, 100,120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380,400 mg every week Head/Neck 1-200 mg/d; 5-20 mg/m²/d for 2-40 mg/m² 2-66Gy total Cancer 1, 5, 10, 15, 20, 3 d; every wk; dose; 25, 30, 35, 40,5, 10, 15, 20 mg/m²/d 2, 5, 10, 15, 20, 2, 5, 10, 15, 20, 45, 50, 55,60, for 3 d; 25, 30, 35, 40 mg/m² 25, 30, 35, 40, 65, 70, 75, 80, 5-10mg/m² every wk; 45, 50, 55, 60, 66 85, 90, 95, 100, every wk; 6-60 mg/m²Gy total dose 105, 110, 115, 5, 7.5, 10 mg/m² every 3 wk; 120, 125, 130,every wk; 6, 10, 15, 20, 25, 135, 140, 145, 10-65 mg/m² 30, 35, 40, 45,150, 155, 160, every 2 wk; 50, 55, 60 mg/m² 165, 170, 175, 10, 15, 20,25, every 3 wk; 180, 185, 190, 30, 35, 40, 45, 6-80 mg/m² 195, 200 mg/d;50, 55, 60, 65 mg/m² every 4 wk; 40-400 mg every every 2 wk; 6, 10, 15,20, 25, wk; 10-100 mg/m² 30, 35, 40, 45, 40-400 mg every every 3 wk; 50,55, 60, 65, wk; 10, 15, 20, 25, 70, 75, 80 mg/m² 40-400 mg every 30, 35,40, 45, every 4 wk wk; 50, 55, 60, 65, 40, 50, 60, 70, 70, 75, 80, 85,80, 90, 100, 120, 90, 95, 100 mg/m² 140, 160, 180, every 3 wk; 200, 220,240, 5-20 mg/m²/d for 260, 280, 300, 5 d every 4 wk; 320, 340, 360, 5,10, 15, 20 mg/m²/d 380, 400 mg for 5 d every week every 4 wk Non-Small1-200 mg/d; 5-30 mg/m²/d for 5-40 mg/m² 2-86 Gy total Cell Lung 1, 5,10, 15, 20, 2 d every 3 wk; every wk; dose; Cancer 25, 30, 35, 40, 5,10, 15, 20, 25, 5, 10, 15, 20, 25, 2, 5, 10, 15, 20, 45, 50, 55, 60, 30mg/m²/d for 2 d 30, 35, 40 mg/m² 25, 30, 35, 40, 65, 70, 75, 80, every 3wk; every wk; 45, 50, 55, 60, 85, 90, 95, 100, 10-100 mg/m² 6-175 mg/m²65, 70, 75, 80, 86 105, 110, 115, every 3 wk; every 3 wk; Gy total dose120, 125, 130, 10, 15, 20, 25, 6, 10, 15, 25, 35, 135, 140, 145, 30, 35,40, 45, 45, 55, 65, 75, 150, 155, 160, 50, 55, 60, 65, 85, 95, 105, 115,165, 170, 175, 70, 75, 80, 85, 125, 135, 145, 180, 185, 190, 90, 95, 100mg/m² 155, 165, 175 mg/m² 195, 200 mg/d; every 3 wk; 8-80 mg/m² 40-400mg every 10-100 mg/m²/d every 4 wk; wk; every 4 wk; 8, 15, 20, 25, 30,40-400 mg every 10, 15, 20, 25, 35, 40, 45, 50, wk; 30, 35, 40, 45, 55,60, 65, 70, 40-400 mg every 50, 55, 60, 65, 75, 80 mg/m² wk; 70, 75, 80,85, every 4 wk 40, 50, 60, 70, 90, 95, 100 mg/m²/d 80, 90, 100, 120,every 4 wk 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360,380, 400 mg every week Melanoma 1-200 mg/d; 10-80 mg/m² 5-100 mg/m² 2-60Gy total 1, 5, 10, 15, 20, every wk; every 3 wk; dose; 25, 30, 35, 40,10, 15, 20, 25, 5, 10, 15, 20, 25, 2, 5, 10, 15, 20, 45, 50, 55, 60, 30,35, 40, 45, 30, 35, 40, 45, 25, 30, 35, 40, 65, 70, 75, 80, 50, 55, 60,65, 50, 55, 60, 65, 45, 50, 55, 60 Gy 85, 90, 95, 100, 70, 75, 80 mg/m²70, 75, 80, 85, total dose 105, 110, 115, every wk; 90, 95, 100 mg/m²120, 125, 130, 5-20 mg/m²/d for every 3 wk; 135, 140, 145, 4 d every 2wk; 8-80 mg/m² 150, 155, 160, 5, 10, 15, 20 mg/m²/d every 4 wk; 165,170, 175, for 4 d 8, 10, 15, 20, 25, 180, 185, 190, every 2 wk; 30, 35,40, 45, 195, 200 mg/d; 5-25 mg/m²/d for 50, 55, 60, 65, 40-400 mg every2 d every 3 wk; 70, 75, 80 mg/m² wk; 5, 10, 15, 20, 25 mg/m²/d every 4wk 40-400 mg every for 2 d wk; every 3 wk; 40-400 mg every 5-30 mg/m²/dfor wk; 3 d every 3 wk; 40, 50, 60, 70, 5, 10, 15, 20, 25, 80, 90, 100,120, 30 mg/m²/d for 3 d 140, 160, 180, every 3 wk; 200, 220, 240, 10-100mg/m² 260, 280, 300, every 3 wk; 320, 340, 360, 10, 15, 20, 25, 380, 400mg 30, 35, 40, 45, every week 50, 55, 60, 65, 70, 75, 80, 85, 90, 95,100 mg/m² every 3 wk Ovarian 1-200 mg/d; 10-100 mg/m² 5-30 mg/m² 2-52 Gytotal Cancer 1, 5, 10, 15, 20, every 3 wk; every wk; dose; 25, 30, 35,40, 10, 15, 20, 25, 5, 10, 15, 20, 25, 2, 5, 10, 15, 20, 45, 50, 55, 60,30, 35, 40, 45, 30 mg/m² every 25, 30, 35, 40, 65, 70, 75, 80, 50, 55,60, 65, wk; 45, 50, 52 Gy 85, 90, 95, 100, 70, 75, 80, 85, 5-60 mg/m²total dose 105, 110, 115, 90, 95, 100 mg/m² every 2 wk; 120, 125, 130,every 3 wk; 5, 10, 15, 20, 25, 135, 140, 145, 10-100 mg/m² 30, 35, 40,45, 150, 155, 160, every 4 wk; 50, 55, 60 mg/m² 165, 170, 175, 10, 15,20, 25, every 2 wk; 180, 185, 190, 30, 35, 40, 45, 10-100 mg/m² 195, 200mg/d; 50, 55, 60, 65, every 3 wk; 40-400 mg every 70, 75, 80, 85, 10,15, 20, 25, wk; 90, 95, 100 mg/m² 30, 35, 40, 45, 40-400 mg every every4 wk 50, 55, 60, 65, wk; 70, 75, 80, 85, 40, 50, 60, 70, 90, 95, 100mg/m² 80, 90, 100, 120, every 3 wk; 140, 160, 180, 6-60 mg/m² 200, 220,240, every 4 wk; 260, 280, 300, 6, 10, 15, 20, 25, 320, 340, 360, 30,35, 40, 45, 380, 400 mg 50, 55, 60 mg/m² every week every 4 wk Lymphoma1-200 mg/d; 5-25 mg/m²/d for 10-100 mg/m² 2-55 Gy total 1, 5, 10, 15,20, 4 d; every 3 wk; dose; 25, 30, 35, 40, 5, 10, 15, 20, 25 mg/m²/d 10,15, 20, 25, 2, 5, 10, 15, 20, 45, 50, 55, 60, for 4 d; 30, 35, 40, 45,25, 30, 35, 40, 65, 70, 75, 80, 10-75 mg/m² 50, 55, 60, 65, 45, 50, 55Gy 85, 90, 95, 100, every 3 wk; 70, 75, 80, 85, total dose 105, 110,115, 10, 15, 20, 25, 90, 95, 100 mg/m² 120, 125, 130, 30, 35, 40, 45,every 3 wk 135, 140, 145, 50, 55, 60, 65, 150, 155, 160, 70, 75 mg/m²165, 170, 175, every 3 wk 180, 185, 190, 195, 200 mg/d; 40-400 mg everywk; 40-400 mg every wk; 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180,200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400 mg every weekHepatoma 1-200 mg/d; 5-30 mg/m² 5-36 mg/m² 2-70 Gy total 1, 5, 10, 15,20, every wk; every wk; dose; 25, 30, 35, 40, 5, 10, 15, 20, 25, 5, 10,15, 20, 25, 2, 5, 10, 15, 20, 45, 50, 55, 60, 30 mg/m² every 30, 36mg/m² 25, 30, 35, 40, 65, 70, 75, 80, wk; every wk; 45, 50, 55, 60, 85,90, 95, 100, 10-80 mg/m²; 5-40 mg/m² 65, 70 Gy total 105, 110, 115, 10,15, 20, 25, every 3 wk; dose 120, 125, 130, 30, 35, 40, 45, 5, 10, 15,20, 25, 135, 140, 145, 50, 55, 60, 65, 30, 35, 40 mg/m² 150, 155, 160,70, 75, 80 mg/m² every 3 wk; 165, 170, 175, 10-60 mg/m² 180, 185, 190,every 4 wk; 195, 200 mg/d; 10, 15, 20, 25, 40-400 mg every 30, 35, 40,45, wk; 50, 55, 60 mg/m² 40-400 mg every every 4 wk wk; 40, 50, 60, 70,80, 90, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340,360, 380, 400 mg every week Sarcoma 1-200 mg/d; 5-20 mg/m²/d for 4-100mg/m² 2-66 Gy total 1, 5, 10, 15, 20, 5 d every 3 wk; every 3 wk; dose;25, 30, 35, 40, 5, 10, 15, 20 mg/m²/d 4, 10, 15, 20, 25, 2, 5, 10, 15,20, 45, 50, 55, 60, for 5 d 30, 35, 40, 45, 25, 30, 35, 40, 65, 70, 75,80, every 3 wk; 50, 55, 60, 65, 45, 50, 55, 60, 66 85, 90, 95, 100, 5-20mg/m²/d for 70, 75, 80, 85, Gy total dose 105, 110, 115, 5 d every 4 wk;90, 95, 100 mg/m² 120, 125, 130, 5, 10, 15, 20 mg/m²/d every 3 wk 135,140, 145, for 5 d 150, 155, 160, every 4 wk; 165, 170, 175, 5-30 mg/m²;180, 185, 190, 5, 10, 15, 20, 25, 195, 200 mg/d; 30 mg/m² 40-400 mgevery wk; 40-400 mg every wk; 40, 50, 60, 70, 80, 90, 100, 120, 140,160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400 mg everyweek Chronic 1-200 mg/d; 5-35 mg/m²/d for 2-8 Gy total Lymphocytic 1, 5,10, 15, 20, 2 d; dose; Leukemia 25, 30, 35, 40, 5, 10, 15, 20, 25, 2, 4,6, 8 Gy total 45, 50, 55, 60, 30, 35 mg/m²/d dose 65, 70, 75, 80, for 2d; 85, 90, 95, 100, 5-25 mg/m²/d for 105, 110, 115, 4 d; 120, 125, 130,5, 10, 15, 20, 25 mg/m²/d 135, 140, 145, for 4 d 150, 155, 160, 165,170, 175, 180, 185, 190, 195, 200 mg/d; 40-400 mg every wk; 40-400 mgevery wk; 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, 220,240, 260, 280, 300, 320, 340, 360, 380, 400 mg every week Acute 1-200mg/d; 2-45 Gy total Myelogenous 1, 5, 10, 15, 20, dose; Leukemia 25, 30,35, 40, 2, 5, 10, 15, 20, 45, 50, 55, 60, 25, 30, 35, 40, 45 65, 70, 75,80, Gy total dose 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135,140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200 mg/d;40-400 mg every wk; 40-400 mg every wk; 40, 50, 60, 70, 80, 90, 100,120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380,400 mg every week Multiple 1-200 mg/d; 10-75 mg/m² 2-40 Gy total Myeloma1, 5, 10, 15, 20, every 3 wk; dose; 25, 30, 35, 40, 10, 15, 20, 25, 2,5, 10, 15, 20, 45, 50, 55, 60, 30, 35, 40, 45, 25, 30, 35, 40 Gy 65, 70,75, 80, 50, 55, 60, 65, total dose 85, 90, 95, 100, 70, 75 mg/m² 105,110, 115, every 3 wk 120, 125, 130, 135, 140, 145, 150, 155, 160, 165,170, 175, 180, 185, 190, 195, 200 mg/d; 40-400 mg every wk; 40-400 mgevery wk; 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, 220,240, 260, 280, 300, 320, 340, 360, 380, 400 mg every week

TABLE 3 Gemcitabine CHOP Carboplatin Doxorubicin Breast 100-1200 mg/m²C-100-1000 mg/m²; 40-265 mg/m²/d 2-20 mg/m² Cancer every wk; H-10-50mg/m²; for 4 d; every wk; 100, 200, 300, O-1-2 mg/m²; 40, 80, 120, 160,2, 4, 6, 8, 10, 12, 400, 500, 600, P-10-40 mg; 200, 265 mg/m²/d 14, 16,18, 20 mg/m² 700, 800, 900, C-100, 200, 300, for 4 d; every wk; 100,1100, 1200 mg/m² 400, 500, 600, 5-20 mg/m²/d for 10-75 mg/m² every wk;700, 800, 900, 20 d; every 2 wk; 100-2,000 mg/m² 1000 mg/m²; 5, 10, 15,20 mg/m²/d 10, 20, 30, 40, every 2 wk; H-10, 20, 30, 40, for 20 d; 50,60, 75 mg/m² 100, 200, 400, 50 mg/m²; 50-300 mg/m² every 2 wk; 600, 800,1000, O-1, 1.2, 1.4, every 4 wk; 10-75 mg/m² 1200, 1400, 1.6, 1.8, 2mg/m²; 50, 100, 150, every 3 wk; 1600, 1800, 2000 mg/m² P-10, 20, 30, 40mg 200, 250, 300 mg/m² 10, 20, 30, 40, every 2 wk; every 4 wk; 50, 60,75 mg/m² 150-1500 mg/m² 500-1600 mg/m²; every 3 wk; every 3 wk; 500,750, 1000, 10-50 mg/m² 150, 300, 600, 1250, 1600 mg/m² every 4 wk; 900,1200, 1500 mg/m² 10, 15, 20, 25, every 3 wk 30, 35, 40, 45, 50 mg/m²every 4 wk; 5-30 mg/m²/d for 3 d every 4 wk; 5, 10, 15, 20, 25, 30mg/m²/d for 3 d every 4 wk Prostate 60-1200 mg/m² 40-800 mg/m² 2-20mg/m² Cancer every 2 wk; every 4 wk; every wk; 60, 120, 200, 40, 100,200, 2, 4, 6, 8, 10, 12, 400, 600, 800, 300, 400, 500, 14, 16, 18, 20mg/m² 100, 1200 mg/m² 600, 700, 800 mg/m² every wk; every 2 wk every 4wk; 4-50 mg/m² 2-20 mg/m²/d for every 3 wk; 21 d every 6 wk; 4, 10, 15,20, 25, 2, 4, 8, 12, 16, 20 mg/m²/d 30, 35, 40, 45, 50 mg/m² for 21 devery 3 wk; every 6 wk 3-50 mg/m² every 4 wk; 3, 6, 10, 15, 20, 25, 30,35, 40, 45, 50 mg/m² every 4 wk Colon 60-2200 mg/m² 2-20 mg/m²/d for3-30 mg/m² Cancer every wk; 20 d; every wk; 60, 120, 200, 2, 4, 8, 12,16, 20 mg/m²/d 3, 6, 10, 15, 20, 400, 600, 800, for 20 d 25, 30 mg/m²1000, 1200, every wk; 1400, 1600, 1-15 mg/m²/d for 1800, 2000, 2200mg/m² 4 d; every wk 1, 3, 5, 7, 9, 11, 13, 15 mg/m²/d for 4 d Pancreatic100-1500 mg/m² 10-100 mg/m² 4-40 mg/m² Cancer every wk; every wk; every3 wk; 100, 300, 500, 10, 20, 30, 40, 4, 8, 12, 16, 20, 700, 900, 1100,50, 60, 70, 80, 24, 28, 32, 36, 40 mg/m² 1300, 1500 mg/m² 90, 100 mg/m²every 3 wk; every wk every wk; 2-40 mg/m² 30-300 mg/m² every 4 wk; every3 wk; 2, 4, 8, 12, 16, 30, 60, 90, 120, 20, 24, 28, 32, 150, 180, 210,36, 40 mg/m² 240, 270, 300 mg/m² every 4 wk every 3 wk; 20-200 mg/m²every 8 wk; 20, 40, 60, 80, 100, 120, 140, 160, 180, 200 mg/m² every 8wk Head/Neck 50-1800 mg/m² 10-90 mg/m² 2-20 mg/m² Cancer every wk; everywk; every wk; 50, 150, 300, 10, 20, 30, 40, 2, 4, 6, 8, 10, 12, 600,900, 1200, 50, 60, 70, 80, 90 mg/m² 14, 16, 18, 20 mg/m² 1500, 1800mg/m² every wk; every wk; every wk 10-70 mg/m²/d 5-75 mg/m² for 5 devery 4 wk; every 3 wk; 10, 20, 30, 40, 5, 15, 25, 35, 45, 50, 60, 70mg/m²/d 55, 65, 75 mg/m² for 5 d every 3 wk; every 4 wk 5-30 mg/m² every4 wk; 5, 10, 15, 20, 25, 30 mg/m² every 4 wk; 5-30 mg/m²/d for 3 d every4 wk 5, 10, 15, 20, 25, 30 mg/m²/d for 3 d every 4 wk Non-Small 75-1500mg/m² 4-40 mg/m²/d for 5-55 mg/m² Cell Lung every wk; 33 d; every 2 wk;Cancer 75, 150, 300, 4, 10, 15, 20, 25, 5, 10, 15, 20, 25, 600, 900,1200, 30, 35, 40 mg/m²/d 30, 35, 40, 45, 1500 mg/m² for 33 d 50, 55mg/m² every wk every 2 wk; 5-50 mg/m² every 3 wk; 5, 10, 15, 20, 25, 30,35, 40, 45, 50 mg/m² every 3 wk; 5-30 mg/m² every 4 wk; 5, 10, 15, 20,25, 30 mg/m² every 4 wk Melanoma 80-1000 mg/m² 40-400 mg/m² 5-50 mg/m²every wk; every 3 wk; every 3 wk; 80, 150, 300, 40, 80, 120, 160, 5, 10,15, 20, 25, 500, 750, 1000 mg/m² 200, 240, 280, 30, 35, 40, 45, 50 mg/m²every wk 320, 360, 400 mg/m² every 3 wk every 3 wk; 30-400 mg/m² every 4wk; 30, 50, 100, 150, 200, 250, 300, 350, 400 mg/m² every 4 wk Ovarian60-1250 mg/m² 30-360 mg/m² 4-50 mg/m² Cancer every wk; every 4 wk; everywk; 60, 120, 250, 30, 60, 90, 120, 4, 10, 15, 20, 25, 500, 750, 1000,150, 180, 210, 30, 35, 40, 45, 50 mg/m² 1250 mg/m² 240, 270, 300, everywk; every wk; 330, 360 mg/m² 5-75 mg/m² 80-2000 mg/m² every 4 wk every 3wk; every 2 wk; 5, 15, 25, 35, 45, 80, 2090, 400, 55, 65, 75 mg/m² 600,800, 1000, every 3 wk; 1200, 1400, 5-30 mg/m²/d for 1600, 1800, 2000mg/m² 3 d every 4 wk; every 2 wk 5, 10, 15, 20, 25, 30 mg/m²/d for 3 devery 4 wk; 5-40 mg/m²/d for 4 d; 5, 10, 15, 20, 25, 30, 35, 40 mg/m²/dfor 4 d Lymphoma 80-1250 mg/m² C-100-1500 mg/m²; 30-300 mg/m² 2-20 mg/m²every wk; H-10-70 mg/m²; every 3 wk; every wk; 80, 150, 250, O-1-2mg/m²; 30, 60, 90, 120, 2, 4, 6, 8, 10, 12, 500, 750, 1000, P-10-100 mg;150, 180, 210, 14, 16, 18, 20 mg/m² 1250 mg/m² C-100, 300, 500, 240,270, 300 mg/m² every wk; every wk; 700, 900, 1100, every 3 wk; 5-75mg/m² 1500-2000 mg/m² 1300, 1500 mg/m²; 30-400 mg/m² every 3 wk; every 2wk; H-10, 30, 50, 70 mg/m²; every 4 wk; 5, 15, 25, 35, 45, 1500, 1600,O-1, 1.2, 1.4, 30, 50, 100, 150, 55, 65, 75 mg/m² 1700, 1800, 1.6, 1.8,2 mg/m²; 200, 250, 300, every 3 wk; 1900, 2000 mg/m² P-10, 20, 30, 40,350, 400 mg/m² 5-80 mg/m² every 2 wk; 50, 60, 70, 80, every 4 wk every 4wk; 2-10 mg/m²/min 90, 100 mg 5, 10, 15, 20, 25, for 12 hr; 30, 35, 40,45, 2, 4, 6, 8, 10 mg/m²/min 50, 55, 60, 65, for 70, 75, 80 mg/m² 12 hrevery 4 wk; 3-30 mg/m²/d for 3 d every 4 wk; 3, 6, 10, 15, 20, 25, 30mg/m²/d for 3 d every 4 wk Hepatoma 70-700 mg/m² 2-20 mg/m² every 3 wk;every wk; 70, 150, 300, 2, 4, 6, 8, 10, 12, 450, 600, 700 mg/m² 14, 16,18, 20 mg/m² every 3 wk; every wk; 25-560 mg/m² 4-60 mg/m² every 4 wk;every 3 wk; 25, 50, 100, 150, 4, 10, 15, 20, 25, 200, 250, 300, 30, 35,40, 45, 350, 400, 450, 50, 55, 60 mg/m² 500, 560 mg/m² every 3 wk; every4 wk 3-50 mg/m² every 4 wk; 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50mg/m² every 4 wk Sarcoma 50-500 mg/m² 3-60 mg/m² every 3 wk; every 3 wk;50, 100, 150, 3, 5, 10, 15, 20, 200, 250, 300, 25, 30, 35, 40, 350, 400,450, 45, 50, 55, 60 mg/m² 500 mg/m² every every 3 wk; 3 wk; 5-75 mg/m²30-300 mg/m² every 4 wk; every 4 wk; 5, 15, 25, 35, 45, 30, 60, 90, 120,55, 65, 75 mg/m² 150, 180, 210, every 4 wk; 240, 270, 300 mg/m² 2-20mg/m²/d for every 4 wk; 3 d; 30-300 mg/m²/d 2, 4, 6, 8, 10, 12, for 4 d;14, 16, 18, 20 mg/m²/d 30, 60, 90, 120, for 3 d; 150, 180, 210, 1-4mg/m²/d for 240, 270, 300 mg/m²/d 4 d; for 4 d 1, 1.5, 2, 2.5, 3, 3.5, 4mg/m²/d for 4 d Chronic C-100-1500 mg/m²; 5-50 mg/m²; LymphocyticH-10-70 mg/m²; 5, 10, 15, 20, 25, Leukemia O-1-2 mg/m²; 30, 35, 40, 45,50 mg/m²; P-10-100 mg; 3-36 mg/m²/d for C-100, 300, 500, 4 d every 3 wk700, 900, 1100, 3, 6, 9, 12, 15, 1300, 1500 mg/m²; 18, 21, 24, 27, H-10,30, 50, 70 mg/m²; 30, 33, 36 mg/m²/d O-1, 1.2, 1.4, for 4 d 1.6, 1.8, 2mg/m²; every 3 wk P-10, 20, 30, 40, 50, 60, 70, 80, 90, 100 mg Acute15-150 mg/m²/d 2-25 mg/m² Myelogenous for 3 d every wk; every wk;Leukemia 15, 30, 45, 60, 2, 5, 10, 15, 20, 75, 90, 105, 120, 25 mg/m²every 135, 150 mg/m²/d wk; for 3 d 2-25 mg/m²/d for every wk; 3 d;30-315 mg/m²/d 2, 5, 10, 15, 20, for 5 d every 2 wk; 25 mg/m²/d for 3 d;30, 60, 90, 120, 5-50 mg/m²; 150, 180, 210, 5, 10, 15, 20, 25, 240, 270,315 mg/m²/d 30, 35, 40, 45, 50 mg/m² for 5 d every 2 wk; 20-216 mg/m²/dfor 5 d; 20, 50, 80, 110, 140, 170, 216 mg/m²/d for 5 d Multiple 10-200mg/m²/d 3-30 mg/m² Myeloma for 4 d; every 3 wk; 10, 25, 50, 75, 3, 6,10, 15, 20, 100, 125, 150, 25, 30 mg/m² 175, 200 mg/m²/d every 3 wk; for4 d; 3-50 mg/m²; 40-400 mg/m² 3, 6, 10, 15, 20, every 4 wk; 25, 30, 35,40, 40, 80, 120, 160, 45, 50 mg/m² 200, 240, 280, 320, 360, 400 mg/m²every 4 wk

TABLE 4 Oxaliplatin Bortezomib Gefitinib Bevacizumab Colon 10-85 mg/m²5-10 mg/kg Cancer every 2 wk; every 2 wk; 10, 15, 20, 25, 5, 6, 7, 8, 9,10 mg/kg 30, 35, 40, 45, every 2 wk 50, 55, 60, 65, 70, 75, 80, 85 mg/m²every 2 wk; 10-130 mg/m² every 3 wk; 10, 20, 30, 40, 50, 60, 70, 80, 90,100, 110, 120, 130 mg/m² every 3 wk Pancreatic 10-100 mg/m² Cancer everywk; 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 mg/m² every wk; 8, 15, 20,25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 mg/m² every 2 wk;8-85 mg/m² every 2 wk Head/Neck 5-60 mg/m² 25-500 mg/d; Cancer every wk;25, 50, 75, 100, 5, 10, 15, 20, 25, 150, 200, 250, 30, 35, 40, 45, 300,350, 400, 50, 55, 60 mg/m² 450, 500 mg/d every wk Non-Small 5-65 mg/m²25-500 mg/d; Cell Lung every wk; 25, 50, 75, 100, Cancer 5, 10, 15, 20,25, 150, 200, 250, 30, 35, 40, 45, 300, 350, 400, 50, 55, 60, 65 mg/m²450, 500 mg/d every wk; 10-130 mg/m² every 3 wk; 10, 20, 30, 40, 50, 60,70, 80, 90, 100, 110, 120, 130 mg/m² every 3 wk Ovarian 10-130 mg/m²Cancer every wk; 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130mg/m² every wk Lymphoma 0.2-1.04 mg/m² 2x wk; 0.2, 0.3, 0.4, 0.5, 0.6,0.7, 0.8, 0.9, 1.04 mg/m² 2x wk Multiple 0.1-1.3 mg/m² 2x Myeloma wk;0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3 mg/m² 2xwk

Since racemic gossypol achieves significant inhibition of tumor growthat a daily dose of about 30 mg/kg, this dose level was initiallyselected for testing gossypol in combination with conventionalanticancer therapeutics. A group of 10 mice received an orallyadministered daily dose of 30 mg/kg gossypol starting at day 7 andlasting for 4 weeks. Also starting at day 7, the same 10 mice wereadministered a weekly i.p. dose (7.5 mg/kg) of docetaxel for 3 weeks.The results of this experiment are shown in FIG. 15. In particular, FIG.15 shows the inhibition of tumor growth by gossypol, or by gossypol anddocetaxel in human breast cancer xenograft MDA-MB-231 nude mice. Eachexperimental group had 10 animals. FIG. 15 shows that administration ofgossypol alone (30 mg/kg daily), or docetaxel alone in a sub-optimaldose (7.5 mg/kg weekly), significantly inhibited tumor growth in thetest animals, however, test animals that received a combination therapyof gossypol and docetaxel showed even greater tumor growth inhibition.Importantly, 3 out of 10 mice (6 tumors) treated with a combinationgossypol and docetaxel showed complete tumor regression. Overall, therewas more than 90% inhibition in tumor growth in the combination therapygroup as compared to the control group. Statistical analyses wereperformed using the SAS (See, G. Verbeke and G. Molenberghs, Linearmixed models in practice: An SAS-orientated approach, Springer-Verlag,vol. 126 (1997)) program. Results of these experiments are provided inTable 5.

TABLE 5 Control Gossypol Docetaxel Racemic Gossypol 0.008* (0.06^(‡))Docetaxel 0.003 (0.01) Racemic Gossypol + 0.00001 0.005 0.01 Docetaxel(0.0000004) (0.009) (0.002) *day 41 ^(‡)day 47

The results show that the anticancer activity of gossypol and docetaxelis statistically significant as compared to controls at both day 41 andday 47 of the study. Furthermore, the anticancer activity of thecombination of gossypol and docetaxel is significant as compared to thecontrol (untreated) groups, and to the groups treated with gossypol ordocetaxel alone. Taken together, these data indicate that gossypol has asignificant anticancer activity alone, but in some embodiments achieveseven greater activity when administered in combination with aconventional anticancer agent (e.g., chemotherapeutic such asdocetaxel).

Although an understanding of any mechanism is not necessary to practicethe present invention and the present invention is not so limited, it iscontemplated that the synergistic effects observed in some combinationsof conventional anticancer agents and gossypol compounds are due to asimilarity of the compounds' mechanisms of action (e.g. induction ofapoptosis). For example, in one embodiment (−)-gossypol enantiomerco-administered with the conventional anticancer therapeutic agent TAXOLprovides a synergistic benefit. FIG. 16 shows the synergistic effects ofco-administration of (−)-gossypol enantiomer and TAXOL. Briefly, thisexperiment used (−)-gossypol or (+)-gossypol in a fixed ratio to TAXOLin a MCF-7 breast cancer cell line ((−)-gossypol IC₅₀ 8.71 μM;(+)-gossypol IC₅₀ 22.88 μM; TAXOL+(−)-gossypol IC₅₀ 2.755 μM; andTAXOL+(+)-gossypol IC₅₀ 10.57 μM). FIGS. 17A and 17B show that there isa strong synergy between (−)-gossypol and TAXOL as well as between(+)-gossypol and TAXOL.

VII. Therapeutic Agents Combined or Co-Administered with GossypolCompounds

A wide range of therapeutic agents find use with the present invention.Any therapeutic agent that can be co-administered with gossypolcompounds, or associated with gossypol compounds is suitable for use inthe methods of the present invention.

Some embodiments of the present invention provide methods foradministering an effective amount of gossypol (acids, enantiomers,isomers, metabolites, derivatives, and pharmaceutically acceptable saltsthereof) and at least one additional non-gossypol therapeutic agent(e.g., including, but not limited to, chemotherapeutic antineoplastics,antimicrobials, antivirals, antifungals, and anti-inflammatory agents)and/or therapeutic technique (e.g., surgical intervention,radiotherapies). In some of these embodiments, the subject has a diseasecharacterized by the intracellular overexpression of Bcl-2 familyproteins (e.g. Bcl-2 and/or Bcl-X_(L)).

Various classes of antineoplastic (e.g., anticancer) agents arecontemplated for use in certain embodiments of the present invention.Anticancer agents suitable for use with the present invention include,but are not limited to, agents that induce apoptosis, agents thatinhibit adenosine deaminase function, inhibit pyrimidine biosynthesis,inhibit purine ring biosynthesis, inhibit nucleotide interconversions,inhibit ribonucleotide reductase, inhibit thymidine monophosphate (TMP)synthesis, inhibit dihydrofolate reduction, inhibit DNA synthesis, formadducts with DNA, damage DNA, inhibit DNA repair, intercalate with DNA,deaminate asparagines, inhibit RNA synthesis, inhibit protein synthesisor stability, inhibit microtubule synthesis or function, and the like.

In some embodiments, exemplary anticancer agents suitable for use incompositions and methods of the present invention include, but are notlimited to: 1) alkaloids, including microtubule inhibitors (e.g.,vincristine, vinblastine, and vindesine, etc.), microtubule stabilizers(e.g., paclitaxel (TAXOL), and docetaxel, etc.), and chromatin functioninhibitors, including topoisomerase inhibitors, such asepipodophyllotoxins (e.g., etoposide (VP-16), and teniposide (VM-26),etc.), and agents that target topoisomerase I (e.g., camptothecin andisirinotecan (CPT-11), etc.); 2) covalent DNA-binding agents (alkylatingagents), including nitrogen mustards (e.g., mechlorethamine,chlorambucil, cyclophosphamide, ifosphamide, and busulfan (MYLERAN),etc.), nitrosoureas (e.g., carmustine, lomustine, and semustine, etc.),and other alkylating agents (e.g., dacarbazine, hydroxymethylmelamine,thiotepa, and mitomycin, etc.); 3) noncovalent DNA-binding agents(antitumor antibiotics), including nucleic acid inhibitors (e.g.,dactinomycin (actinomycin D), etc.), anthracyclines (e.g., daunorubicin(daunomycin, and cerubidine), doxorubicin (adriamycin), and idarubicin(idamycin), etc.), anthracenediones (e.g., anthracycline analogues, suchas mitoxantrone, etc.), bleomycins (BLENOXANE), etc., and plicamycin(mithramycin), etc.; 4) antimetabolites, including antifolates (e.g.,methotrexate, FOLEX, and MEXATE, etc.), purine antimetabolites (e.g.,6-mercaptopurine (6-MP, PURINETHOL), 6-thioguanine (6-TG), azathioprine,acyclovir, ganciclovir, chlorodeoxyadenosine, 2-chlorodeoxyadenosine(CdA), and 2′-deoxycoformycin (pentostatin), etc.), pyrimidineantagonists (e.g., fluoropyrimidines (e.g., 5-fluorouracil (ADRUCIL),5-fluorodeoxyuridine (FdUrd) (floxuridine)) etc.), and cytosinearabinosides (e.g., CYTOSAR (ara-C) and fludarabine, etc.); 5) enzymes,including L-asparaginase, and hydroxyurea, etc.; 6) hormones, includingglucocorticoids, antiestrogens (e.g. tamoxifen, etc.), nonsteroidalantiandrogens (e.g., flutamide, etc.), and aromatase inhibitors (e.g.,anastrozole (ARIMIDEX), etc.); 7) platinum compounds (e.g., cisplatinand carboplatin, etc.); 8) monoclonal antibodies conjugated withanticancer drugs, toxins, and/or radionuclides, etc.; 9) biologicalresponse modifiers (e.g., interferons (e.g., IFN-α, etc.) andinterleukins (e.g., IL-2, etc.), etc.); 10) adoptive immunotherapy; 11)hematopoietic growth factors; 12) agents that induce tumor celldifferentiation (e.g., all-trans-retinoic acid, etc.); 13) gene therapytechniques; 14) antisense therapy techniques; 15) tumor vaccines; 16)therapies directed against tumor metastases (e.g., batimastat, etc.);17) angiogenesis inhibitors; 18) proteosome inhibitors (e.g., VELCADE);19) inhibitors of acetylation and/or methylation (e.g., HDACinhibitors); 20) modulators of NF kappa B; 21) inhibitors of cell cycleregulation (e.g., CDK inhibitors); 22) modulators of p53 proteinfunction; and 23) radiation.

Any oncolytic agent that is routinely used in a cancer therapy contextfinds use in the compositions and methods of the present invention. Forexample, the U.S. Food and Drug Administration maintains a formulary ofoncolytic agents approved for use in the United States. Internationalcounterpart agencies to the U.S.F.D.A. maintain similar formularies.Table 6 provides a list of exemplary antineoplastic agents approved foruse in the U.S. Those skilled in the art will appreciate that the“product labels” required on all U.S. approved chemotherapeuticsdescribe approved indications, dosing information, toxicity data, andthe like, for the exemplary agents.

TABLE 6 Aldesleukin Proleukin Chiron Corp., (des-alanyl-1, serine-125human interleukin-2) Emeryville, CA Alemtuzumab Campath Millennium and(IgG1κ anti CD52 antibody) ILEX Partners, LP, Cambridge, MA AlitretinoinPanretin Ligand (9-cis-retinoic acid) Pharmaceuticals, Inc., San DiegoCA Allopurinol Zyloprim GlaxoSmithKline,(1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one Research Trianglemonosodium salt) Park, NC Altretamine Hexalen US Bioscience, West(N,N,N′,N′,N″,N″,-hexamethyl-1,3,5-triazine-2,4, Conshohocken, PA6-triamine) Amifostine Ethyol US Bioscience (ethanethiol,2-[(3-aminopropyl)amino]-, dihydrogen phosphate (ester)) AnastrozoleArimidex AstraZeneca (1,3-Benzenediacetonitrile, a,a,a′,a′-tetramethyl-Pharmaceuticals, LP, 5-(1H-1,2,4-triazol-1-ylmethyl)) Wilmington, DEArsenic trioxide Trisenox Cell Therapeutic, Inc., Seattle, WAAsparaginase Elspar Merck & Co., Inc., (L-asparagine amidohydrolase,type EC-2) Whitehouse Station, NJ BCG Live TICE BCG Organon Teknika,(lyophilized preparation of an attenuated strain of Corp., Durham, NCMycobacterium bovis (Bacillus Calmette-Gukin [BCG], substrain Montreal)bexarotene capsules Targretin Ligand(4-[1-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2- Pharmaceuticalsnapthalenyl) ethenyl] benzoic acid) bexarotene gel Targretin LigandPharmaceuticals Bleomycin Blenoxane Bristol-Myers Squibb (cytotoxicglycopeptide antibiotics produced by Co., NY, NY Streptomycesverticillus; bleomycin A₂ and bleomycin B₂) Capecitabine Xeloda Roche(5′-deoxy-5-fluoro-N-[(pentyloxy)carbonyl]- cytidine) CarboplatinParaplatin Bristol-Myers Squibb (platinum, diammine [1,1-cyclobutanedicarboxylato(2-)-0,0′]-,(SP-4-2)) Carmustine BCNU, BiCNUBristol-Myers Squibb (1,3-bis(2-chloroethyl)-1-nitrosourea) Carmustinewith Polifeprosan 20 Implant Gliadel Wafer Guilford Pharmaceuticals,Inc., Baltimore, MD Celecoxib Celebrex Searle (as4-[5-(4-methylphenyl)-3-(trifluoromethyl)- Pharmaceuticals,1H-pyrazol-1-yl] England benzenesulfonamide) Chlorambucil LeukeranGlaxoSmithKline (4-[bis(2chlorethyl)amino]benzenebutanoic acid)Cisplatin Platinol Bristol-Myers Squibb (PtCl₂H₆N₂) CladribineLeustatin, 2-CdA R. W. Johnson (2-chloro-2′-deoxy-b-D-adenosine)Pharmaceutical Research Institute, Raritan, NJ Cyclophosphamide Cytoxan,Neosar Bristol-Myers Squibb (2-[bis(2-chloroethyl)amino]tetrahydro-2H-13,2- oxazaphosphorine 2-oxide monohydrate) CytarabineCytosar-U Pharmacia & Upjohn (1-b-D-Arabinofuranosylcytosine, C₉H₁₃N₃O₅)Company cytarabine liposomal DepoCyt Skye Pharmaceuticals, Inc., SanDiego, CA Dacarbazine DTIC-Dome Bayer AG,(5-(3,3-dimethyl-1-triazeno)-imidazole-4- Leverkusen, carboxamide(DTIC)) Germany Dactinomycin, actinomycin D Cosmegen Merck (actinomycinproduced by Streptomyces parvullus, C₆₂H₈₆N₁₂O₁₆) Darbepoetin alfaAranesp Amgen, Inc., (recombinant peptide) Thousand Oaks, CAdaunorubicin liposomal DanuoXome Nexstar((8S-cis)-8-acetyl-10-[(3-amino-2,3,6-trideoxy-á- Pharmaceuticals, Inc.,L-lyxo-hexopyranosyl)oxy]-7,8,9,10-tetrahydro- Boulder, CO6,8,11-trihydroxy-1-methoxy-5,12- naphthacenedione hydrochloride)Daunorubicin HCl, daunomycin Cerubidine Wyeth Ayerst,((1S,3S)-3-Acetyl-1,2,3,4,6,11-hexahydro- Madison, NJ3,5,12-trihydroxy-10-methoxy-6,11-dioxo-1- naphthacenyl3-amino-2,3,6-trideoxy-(alpha)-L- lyxo-hexopyranoside hydrochloride)Denileukin diftitox Ontak Seragen, Inc., (recombinant peptide)Hopkinton, MA Dexrazoxane Zinecard Pharmacia & Upjohn((S)-4,4′-(1-methyl-1,2-ethanediyl)bis-2,6- Company piperazinedione)Docetaxel Taxotere Aventis ((2R,3S)—N-carboxy-3-phenylisoserine, N-tert-Pharmaceuticals, Inc., butyl ester, 13-ester with 5b-20-epoxy-Bridgewater, NJ 12a,4,7b,10b,13a-hexahydroxytax-11-en-9-one 4- acetate2-benzoate, trihydrate) Doxorubicin HCl Adriamycin, Pharmacia & Upjohn(8S,10S)-10-[(3-amino-2,3,6-trideoxy-a-L-lyxo- Rubex Companyhexopyranosyl)oxy]-8-glycolyl-7,8,9,10-tetrahydro-6,8,11-trihydroxy-1-methoxy-5,12- naphthacenedionehydrochloride) doxorubicin Adriamycin PFS Pharmacia & Upjohn IntravenousCompany injection doxorubicin liposomal Doxil Sequus Pharmaceuticals,Inc., Menlo park, CA dromostanolone propionate Dromostanolone Eli Lilly& Company, (17b-Hydroxy-2a-methyl-5a-androstan-3-one Indianapolis, INpropionate) dromostanolone propionate Masterone Syntex, Corp., Paloinjection Alto, CA Elliott's B Solution Elliott's B Orphan Medical, IncSolution Epirubicin Ellence Pharmacia & Upjohn((8S-cis)-10-[(3-amino-2,3,6-trideoxy-a-L- Companyarabino-hexopyranosyl)oxy]-7,8,9,10-tetrahydro-6,8,11-trihydroxy-8-(hydroxyacetyl)-1-methoxy- 5,12-naphthacenedionehydrochloride) Epoetin alfa Epogen Amgen, Inc (recombinant peptide)Estramustine Emcyt Pharmacia & Upjohn(estra-1,3,5(10)-triene-3,17-diol(17(beta))-,3- Company[bis(2-chloroethyl)carbamate] 17-(dihydrogen phosphate), disodium salt,monohydrate, or estradiol 3-[bis(2-chloroethyl)carbamate] 17-(dihydrogen phosphate), disodium salt, monohydrate) Etoposide phosphateEtopophos Bristol-Myers Squibb (4′-Demethylepipodophyllotoxin9-[4,6-O-(R)- ethylidene-(beta)-D-glucopyranoside], 4′- (dihydrogenphosphate)) etoposide, VP-16 Vepesid Bristol-Myers Squibb(4′-demethylepipodophyllotoxin 9-[4,6-0-(R)-ethylidene-(beta)-D-glucopyranoside]) Exemestane Aromasin Pharmacia &Upjohn (6-methylenandrosta-1,4-diene-3,17-dione) Company FilgrastimNeupogen Amgen, Inc (r-metHuG-CSF) floxuridine (intraarterial) FUDRRoche (2′-deoxy-5-fluorouridine) Fludarabine Fludara BerlexLaboratories, (fluorinated nucleotide analog of the antiviral Inc.,Cedar Knolls, agent vidarabine, 9-b-D-arabinofuranosyladenine NJ(ara-A)) Fluorouracil, 5-FU Adrucil ICN Pharmaceuticals,(5-fluoro-2,4(1H,3H)-pyrimidinedione) Inc., Humacao, Puerto RicoFulvestrant Faslodex IPR Pharmaceuticals, (7-alpha-[9-(4,4,5,5,5-pentafluoropentylsulphinyl) Guayama, Puertononyl]estra-1,3,5-(10)-triene-3,17-beta-diol) Rico Gemcitabine GemzarEli Lilly (2′-deoxy-2′,2′-difluorocytidine monohydrochloride (b-isomer))Gemtuzumab Ozogamicin Mylotarg Wyeth Ayerst (anti-CD33 hP67.6) Goserelinacetate Zoladex Implant AstraZeneca (acetate salt of[D-Ser(But)⁶,Azgly¹⁰]LHRH; pyro- PharmaceuticalsGlu-His-Trp-Ser-Tyr-D-Ser(But)-Leu-Arg-Pro- Azgly-NH2 acetate[C₅₉H₈₄N₁₈O₁₄•(C₂H₄O₂)_(x) Hydroxyurea Hydrea Bristol-Myers SquibbIbritumomab Tiuxetan Zevalin Biogen IDEC, Inc., (immunoconjugateresulting from a thiourea Cambridge MA covalent bond between themonoclonal antibody Ibritumomab and the linker-chelator tiuxetan [N-[2-bis(carboxymethyl)amino]-3-(p- isothiocyanatophenyl)-propyl]-[N-[2-bis(carboxymethyl)amino]-2-(methyl)- ethyl]glycine) Idarubicin IdamycinPharmacia & Upjohn (5,12-Naphthacenedione, 9-acetyl-7-[(3-amino- Company2,3,6-trideoxy-(alpha)-L-lyxo-hexopyranosyl)oxy]-7,8,9,10-tetrahydro-6,9,11- trihydroxyhydrochloride,(7S-cis)) Ifosfamide IFEX Bristol-Myers Squibb (3-(2-chloroethyl)-2-[(2-chloroethyl)amino]tetrahydro-2H-1,3,2- oxazaphosphorine 2-oxide)Imatinib Mesilate Gleevec Novartis AG, Basel,(4-[(4-Methyl-1-piperazinyl)methyl]-N-[4-methyl- Switzerland3-[[4-(3-pyridinyl)-2-pyrimidinyl]amino]- phenyl]benzamidemethanesulfonate) Interferon alfa-2a Roferon-A Hoffmann-La Roche,(recombinant peptide) Inc., Nutley, NJ Interferon alfa-2b Intron ASchering AG, Berlin, (recombinant peptide) (Lyophilized GermanyBetaseron) Irinotecan HCl Camptosar Pharmacia & Upjohn((4S)-4,11-diethyl-4-hydroxy-9-[(4-piperidinopiperidino) Companycarbonyloxy]-1H-pyrano[3′,4′:6,7] indolizino[1,2-b]quinoline-3,14(4H,12H) dione hydrochloride trihydrate) Letrozole FemaraNovartis (4,4′-(1H-1,2,4-Triazol-1-ylmethylene) dibenzonitrile)Leucovorin Wellcovorin, Immunex, Corp., (L-Glutamic acid,N[4[[(2amino-5-formyl- Leucovorin Seattle, WA 1,4,5,6,7,8hexahydro4oxo6- pteridinyl)methyl]amino]benzoyl], calcium salt (1:1))Levamisole HCl Ergamisol Janssen Research((−)-(S)-2,3,5,6-tetrahydro-6-phenylimidazo [2,1- Foundation, b]thiazole monohydrochloride C₁₁H₁₂N₂S•HCl) Titusville, NJ Lomustine CeeNUBristol-Myers Squibb (1-(2-chloro-ethyl)-3-cyclohexyl-1-nitrosourea)Meclorethamine, nitrogen mustard Mustargen Merck(2-chloro-N-(2-chloroethyl)-N-methylethanamine hydrochloride) Megestrolacetate Megace Bristol-Myers Squibb17α(acetyloxy)-6-methylpregna-4,6-diene- 3,20-dione Melphalan, L-PAMAlkeran GlaxoSmithKline (4-[bis(2-chloroethyl) amino]-L-phenylalanine)Mercaptopurine, 6-MP Purinethol GlaxoSmithKline(1,7-dihydro-6H-purine-6-thione monohydrate) Mesna Mesnex Asta Medica(sodium 2-mercaptoethane sulfonate) Methotrexate Methotrexate LederleLaboratories (N-[4-[[(2,4-diamino-6-pteridinyl)methyl]methylamino]benzoyl]-L- glutamic acid) MethoxsalenUvadex Therakos, Inc., Way(9-methoxy-7H-furo[3,2-g][1]-benzopyran-7-one) Exton, Pa Mitomycin CMutamycin Bristol-Myers Squibb mitomycin C Mitozytrex SuperGen, Inc.,Dublin, CA Mitotane Lysodren Bristol-Myers Squibb(1,1-dichloro-2-(o-chlorophenyl)-2-(p- chlorophenyl) ethane)Mitoxantrone Novantrone Immunex (1,4-dihydroxy-5,8-bis[[2-[(2-Corporation hydroxyethyl)amino]ethyl]amino]-9,10- anthracenedionedihydrochloride) Nandrolone phenpropionate Durabolin-50 Organon, Inc.,West Orange, NJ Nofetumomab Verluma Boehringer Ingelheim Pharma KG,Germany Oprelvekin Neumega Genetics Institute, (IL-11) Inc., Alexandria,VA Oxaliplatin Eloxatin Sanofi Synthelabo,(cis-[(1R,2R)-1,2-cyclohexanediamine-N,N′] Inc., NY, NY[oxalato(2-)-O,O′] platinum) Paclitaxel TAXOL Bristol-Myers Squibb(5β,20-Epoxy-1,2a,4,7β,10β,13a- hexahydroxytax-11-en-9-one4,10-diacetate 2- benzoate 13-ester with (2R,3S)-N-benzoyl-3-phenylisoserine) Pamidronate Aredia Novartis (phosphonic acid(3-amino-1-hydroxypropylidene) bis-, disodium salt, pentahydrate, (APD))Pegademase Adagen Enzon ((monomethoxypolyethylene glycol succinimidyl)(Pegademase Pharmaceuticals, Inc., 11-17-adenosine deaminase) Bovine)Bridgewater, NJ Pegaspargase Oncaspar Enzon (monomethoxypolyethyleneglycol succinimidyl L-asparaginase) Pegfilgrastim Neulasta Amgen, Inc(covalent conjugate of recombinant methionyl human G-CSF (Filgrastim)and monomethoxypolyethylene glycol) Pentostatin Nipent Parke-DavisPharmaceutical Co., Rockville, MD Pipobroman Vercyte AbbottLaboratories, Abbott Park, IL Plicamycin, Mithramycin Mithracin Pfizer,Inc., NY, NY (antibiotic produced by Streptomyces plicatus) Porfimersodium Photofrin QLT Phototherapeutics, Inc., Vancouver, CanadaProcarbazine Matulane Sigma Tau(N-isopropyl-μ-(2-methylhydrazino)-p-toluamide Pharmaceuticals, Inc.,monohydrochloride) Gaithersburg, MD Quinacrine Atabrine Abbott Labs(6-chloro-9-(1-methyl-4-diethyl-amine) butylamino-2-methoxyacridine)Rasburicase Elitek Sanofi-Synthelabo, (recombinant peptide) Inc.,Rituximab Rituxan Genentech, Inc., (recombinant anti-CD20 antibody)South San Francisco, CA Sargramostim Prokine Immunex Corp (recombinantpeptide) Streptozocin Zanosar Pharmacia & Upjohn (streptozocin2-deoxy-2- Company [[(methylnitrosoamino)carbonyl]amino]-a(and b)-D-glucopyranose and 220 mg citric acid anhydrous) Talc Sclerosol Bryan,Corp., (Mg₃Si₄O₁₀(OH)₂) Woburn, MA Tamoxifen Nolvadex AstraZeneca((Z)2-[4-(1,2-diphenyl-1-butenyl) phenoxy]-N,N- Pharmaceuticalsdimethylethanamine 2-hydroxy-1,2,3- propanetricarboxylate (1:1))Temozolomide Temodar Schering(3,4-dihydro-3-methyl-4-oxoimidazo[5,1-d]-as- tetrazine-8-carboxamide)teniposide, VM-26 Vumon Bristol-Myers Squibb(4′-demethylepipodophyllotoxin 9-[4,6-0-(R)-2-thenylidene-(beta)-D-glucopyranoside]) Testolactone Teslac Bristol-MyersSquibb (13-hydroxy-3-oxo-13,17-secoandrosta-1,4-dien- 17-oic acid[dgr]-lactone) Thioguanine, 6-TG Thioguanine GlaxoSmithKline(2-amino-1,7-dihydro-6H-purine-6-thione) Thiotepa Thioplex Immunex(Aziridine, 1,1′,1″-phosphinothioylidynetris-, or Corporation Tris(1-aziridinyl) phosphine sulfide) Topotecan HCl Hycamtin GlaxoSmithKline((S)-10-[(dimethylamino) methyl]-4-ethyl-4,9-dihydroxy-1H-pyrano[3′,4′:6,7] indolizino [1,2-b]quinoline-3,14-(4H,12H)-dione monohydrochloride) Toremifene FarestonRoberts (2-(p-[(Z)-4-chloro-1,2-diphenyl-1-butenyl]- Pharmaceuticalphenoxy)-N,N-dimethylethylamine citrate (1:1)) Corp., Eatontown, NJTositumomab, I 131 Tositumomab Bexxar Corixa Corp., Seattle,(recombinant murine immunotherapeutic WA monoclonal IgG_(2a) lambdaanti-CD20 antibody (I 131 is a radioimmunotherapeutic antibody))Trastuzumab Herceptin Genentech, Inc (recombinant monoclonal IgG₁ kappaanti-HER2 antibody) Tretinoin, ATRA Vesanoid Roche (all-trans retinoicacid) Uracil Mustard Uracil Mustard Roberts Labs Capsules Valrubicin,N-trifluoroacetyladriamycin-14- Valstar Anthra --> Medeva valerate((2S-cis)-2-[1,2,3,4,6,11-hexahydro-2,5,12- trihydroxy-7methoxy-6,11-dioxo-[[4 2,3,6-trideoxy-3-[(trifluoroacetyl)-amino-α-L-lyxo-hexopyranosyl]oxyl]-2-naphthacenyl]-2-oxoethyl pentanoate) Vinblastine,Leurocristine Velban Eli Lilly (C₄₆H₅₆N₄O₁₀•H₂SO₄) Vincristine OncovinEli Lilly (C₄₆H₅₆N₄O₁₀•H₂SO₄) Vinorelbine Navelbine GlaxoSmithKline(3′,4′-didehydro-4′-deoxy-C′- norvincaleukoblastine [R-(R*,R*)-2,3-dihydroxybutanedioate (1:2)(salt)]) Zoledronate, Zoledronic acid ZometaNovartis ((1-Hydroxy-2-imidazol-1-yl-phosphonoethyl) phosphonic acidmonohydrate)

Preferred conventional anticancer agents for use in administration withthe disclosed gossypol compounds include, but are not limited to,adriamycin, 5-fluorouracil, etoposide, camptothecin, actinomycin-D,mitomycin C, cisplatin, docetaxel, gemcitabine, carboplatin,oxaliplatin, bortezomib, gefitinib, and bevacizumab. These agents can beprepared and used singularly, in combined therapeutic compositions, inkits, or in combination with immunotherapeutic agents, and the like.

In preferred embodiments, the present invention provides methods for theadministration of effective amounts of gossypol compounds and at leastone conventional anticancer agent (e.g., an agent that inducesapoptosis). In some preferred embodiments, the subject has a diseasecharacterized by the overexpression of Bcl-2 family protein(s) (e.g.,Bcl-2 and/or Bcl-X_(L)). In yet other preferred embodiments, the presentinvention provides methods for the administration of effective amountsof gossypol compounds and a taxane (e.g., docetaxel) compound tosubjects having diseases characterized by the overexpression of Bcl-2family protein(s) (e.g., Bcl-2 and/or Bcl-X_(L)).

Generally, taxanes (e.g., docetaxel) are an effective class ofanticancer chemotherapeutic agents. (See e.g., K. D. Miller and G. W.Sledge, Jr. Cancer Investigation, 17:121-136 (1999)). While the presentinvention is not limited to any particular mechanism(s), it iscontemplated that taxane-mediated cell death occurs throughintracellular microtubule stabilization and subsequent induction of theapoptotic pathway. (See e.g., S. Haldar et al., Cancer Research,57:229-233 (1997)). In many systems, Bcl-X_(L) functions as a negativecontrol on this pathway.

In some other embodiments, cisplatin and TAXOL are specificallycontemplated for administration with gossypol compounds. Cisplatin andTAXOL induce apoptosis in tumor cells. (See e.g., Lanni et al., Proc.Natl. Acad. Sci., 94:9679 (1997); Tortora et al., Cancer Research57:5107 (1997); and Zaffaroni et al., Brit. J. Cancer 77:1378 (1998)).However, treatment with these and other chemotherapeutic agents isdifficult to accomplish without subjecting the patient to significanttoxicity. Many anticancer chemotherapeutic agents currently in use aregenerally poorly water soluble, toxic, and when given at efficaciouslevels affect normal cells as well as diseased cells.

For example, paclitaxel (TAXOL), is a very promising anticancercompound, and has shown excellent antitumor activity in a wide varietyof tumor models such as the B16 melanoma, L1210 leukemias, MX-1 mammarytumors, and CS-1 colon tumor xenografts. However, is has poor aqueoussolubility which presents a problem in human administration.Accordingly, paclitaxel formulations typically require the use of acremaphor to solubilize the drug. The human clinical dose range ofpaclitaxel is about 110-500 mg/m². For administration, paclitaxel isusually dissolved in a solution of ethanol:cremaphor (1:1) then dilutedinto one liter of water or other aqueous mixture. Polyethoxylated castoroil is the most often used cremaphor. The cremaphor mixture isadministered by infusion. Direct administration (e.g., subcutaneous) ofthe cremaphor mixture results in local toxicity and low levels ofactivity.

In still further embodiments, the present invention provides methods formonitoring the therapeutic success of cisplatin and/or TAXOLadministration in a subject. Measuring the ability of these drugs toinduce apoptosis in vitro is reported to be a marker for in vivoefficacy. (Gibb, Gynecologic Oncology, 65:13 (1997)). The effectivenessof cisplatin and/or TAXOL as anticancer chemotherapeutics can bemeasured using techniques of the present invention for monitoringinduction of apoptosis. Cisplatin and/or TAXOL are active against awide-range of tumor types including, but not limited to, breast cancerand colon cancer. (Akutsu et al., Eur. J. Cancer 31A:2341 (1995)).

In some embodiments of the present invention, therapeutic gossypolcompound treatments further comprise one or more agents that directlycross-link nucleic acids (e.g., DNA) to facilitate DNA damage leading toa synergistic effect. Agents such as cisplatin and other DNA alkylatingagents are preferred. Cisplatin has been widely used in cancertreatments. Efficacious doses used in clinical applications include, butare not limited to, about 20 mg/m² for 5 days every three weeks for atotal of three courses, and 50-120 mg/m² every 3 weeks.

Agents that damage DNA also include compounds that interfere with DNAreplication, mitosis, and chromosomal segregation. Such chemotherapeuticcompounds include, but are not limited to, adriamycin, also known asdoxorubicin, etoposide, verapamil, podophyllotoxin, and the like. Thesecompounds are widely used in clinical settings for the treatment ofneoplasms, and are typically administered as a bolus intravenousinjection at doses ranging from about 25-75 mg/m² at 21 day intervals,20-30 mg/m² every week, and similar doses for adriamycin, and 100-200mg/m² for etoposide for three days every 3-4 weeks intravenously ordouble the intravenous dose when administered orally.

Agents that disrupt the synthesis and fidelity of nucleic acidprecursors and subunits also lead to DNA damage and find use aschemotherapeutic agents in the present invention. A number of nucleicacid precursors have been developed. Particularly useful are agents thathave undergone extensive testing and are readily available.5-Fluorouracil (5-FU) is preferentially used by neoplastic tissues,making this agent particularly useful for targeting to neoplastic cells.The dose of 5-fluorouracil may range from about 3 to 15 mg/kg/day,although other doses may vary considerably according to various factorsincluding stage of disease, amenability of the cells to the therapy,amount of resistance to the agent and the like.

In preferred embodiments, the anticancer agents used in the presentinvention are those that are amenable to co-administration with thedisclosed gossypol compounds or are otherwise associated with thedisclosed gossypol compounds such that they can be delivered into asubject, tissue, or cell without loss of fidelity of anticancer effect.For a more detailed description of cancer therapeutic agents such as aplatinum complex, verapamil, podophyllotoxin, carboplatin, procarbazine,mechlorethamine, cyclophosphamide, camptothecin, ifosfamide, melphalan,chlorambucil, busulfan, nitrosourea, dactinomycin, daunorubicin,doxorubicin (adriamycin), bleomycin, plicomycin, mitomycin, etoposide(VP16), tamoxifen, TAXOL, transplatinum, 5-fluorouracil, vincristin,vinblastin and methotrexate and other similar anti-cancer agents, thoseskilled in the art are referred to any number of instructive manualsincluding, but not limited to, the Physician's Desk Reference and toGoodman and Gilman's “Pharmaceutical Basis of Therapeutics” ninthedition, Eds. Hardman et al., 1996.

In some embodiments, the drugs are attached to the gossypol compoundswith photocleavable linkers. For example, several heterobifunctional,photocleavable linkers that find use with the present invention aredescribed by Ottl et al. (Ottl et al., Bioconjugate Chem., 9:143(1998)). These linkers can be either water or organic soluble. Theycontain an activated ester that can react with amines or alcohols and anepoxide that can react with a thiol group. In between the two groups is3,4-dimethoxy-6-nitrophenyl photoisomerization group, which, whenexposed to near-ultraviolet light (365 nm), releases the amine oralcohol in intact form. Thus, the therapeutic agent, when linked to thecompositions of the present invention using such linkers, may bereleased in biologically active or activatable form through exposure ofthe target area to near-ultraviolet light.

In an exemplary embodiment, the alcohol group of TAXOL is reacted withthe activated ester of the organic-soluble linker. This product in turnis reacted with the partially-thiolated surface of appropriatedendrimers (the primary amines of the dendrimers can be partiallyconverted to thiol-containing groups by reaction with asub-stoichiometric amount of 2-iminothiolano). In the case of cisplatin,the amino groups of the drug are reacted with the water-soluble form ofthe linker. If the amino groups are not reactive enough, a primaryamino-containing active analog of cisplatin, such as Pt(II) sulfadiazinedichloride (Pasani et al., Inorg. Chim. Acta 80:99 (1983) and Abel etal., Eur. J. Cancer 9:4 (1973)) can be used. Thus conjugated, the drugis inactive and will not harm normal cells. When the conjugate islocalized within tumor cells, it is exposed to laser light of theappropriate near-UV wavelength, causing the active drug to be releasedinto the cell.

Similarly, in other embodiments of the present invention, the aminogroups of cisplatin (or an analog thereof) are linked with a veryhydrophobic photocleavable protecting group, such as the2-nitrobenzyloxycarbonyl group (See e.g., Pillai, V. N. R. Synthesis:1-26 (1980)). When exposed to near-UV light (about 365 nm), thehydrophobic group is cleaved, leaving the intact drug. A number ofphotocleavable linkers have been demonstrated as effective anti-tumorconjugates and can be prepared by attaching cancer therapeutics, such asdoxorubicin, to water-soluble polymers with appropriate short peptidelinkers (See e.g., Vasey et al., Clin. Cancer Res., 5:83 (1999)). Thelinkers are stable outside of the cell, but are cleaved bythiolproteases once within the cell. In a preferred embodiment, theconjugate PK1 is used. As an alternative to the photocleavable linkerstrategy, enzyme-degradable linkers, such as Gly-Phe-Leu-Gly (SEQ ID NO:3) may be used. An alternative to photocleavable linkers are enzymecleavable linkers.

The present invention is not limited by the nature of the therapeutictechnique. For example, other conjugates that find use with the presentinvention include, but are not limited to, using conjugated borondusters for BNCT (Capala et al., Bioconjugate Chem., 7:7 (1996)), theuse of radioisotopes, and conjugation of toxins such as ricin.

Antimicrobial therapeutic agents may also be used as therapeutic agentsin the present invention. Any agent that can kill, inhibit, or otherwiseattenuate the function of microbial organisms may be used, as well asany agent contemplated to have such activities. Antimicrobial agentsinclude, but are not limited to, natural and synthetic antibiotics,antibodies, inhibitory proteins (e.g., defensins), antisense nucleicacids, membrane disruptive agents and the like, used alone or incombination. Indeed, any type of antibiotic may be used including, butnot limited to, antibacterial agents, antiviral agents, antifungalagents, and the like.

VIII. Targeting Agents and Techniques

In still further embodiments, the present invention provides gossypolcompounds (and any other chemotherapeutic agents) associated withtargeting agents (gossypol compound-targeting agent complexes) that areable to specifically target particular cell types (e.g., tumor cells).Generally, the gossypol compound that is associated with a targetingagent, targets neoplastic cells through interaction of the targetingagent with a cell surface moiety that is taken into the cell throughreceptor mediated endocytosis.

Any moiety known to be located on the surface of target cells (e.g.,tumor cells) finds use with the present invention. For example, anantibody directed against such a moiety targets the compositions of thepresent invention to cell surfaces containing the moiety. Alternatively,the targeting moiety may be a ligand directed to a receptor present onthe cell surface or vice versa. Similarly, vitamins also may be used totarget the therapeutics of the present invention to a particular cell.

As used herein, the term “targeting molecules” refers to chemicalmoieties, and portions thereof useful for targeting chemical compounds(e.g., gossypol compounds, drugs, prodrugs, small molecules, therapeuticagents) to cells, tissues, and organs of interest. Various types oftargeting molecules are contemplated for use with the present inventionincluding, but not limited to, signal peptides, antibodies, nucleicacids, toxins and the like. Targeting moieties may additionally promotethe binding of the associated chemical compounds (e.g., small molecules)or the entry of the compounds into the targeted cells, tissues, andorgans. Preferably, targeting moieties are selected according to theirspecificity, affinity, and efficacy in selectively delivering attachedcompounds to targeted sites within a subject, tissue, or a cell,including specific subcellular locations and organelles.

In some preferred embodiments, the targeting molecules of the presentinvention are associated with a therapeutic or other small molecule(e.g., gossypol compound, drugs, prodrugs, small molecules, therapeuticagents, etc.). Targeting molecules can be associated to the therapeuticsmall molecules of the present invention using a variety of linking(e.g., cleavable linkers), spacer, and protecting groups. For example,in certain embodiments, targeting moieties are associated (e.g.,covalently or noncovalently bound) to the small molecule therapeuticagents by short (e.g., direct coupling), medium (e.g., usingsmall-molecule bifunctional linkers such as SPDP (Pierce Biotechnology,Inc., Rockford, Ill.)), or long (e.g., PEG bifunctional linkers (NektarTherapeutics, Inc., San Carlos, Calif.)) chemical linkages.

Preferably, the various targeting molecules and therapeutic agents ofthe present invention are attached, associated, fixed, or conjugatedsuch that each entity therein is sufficiently free of steric hindrance(e.g., via connection through a suitable linker) such that its chemicalor biological activity is, at least partially, retained.

The small molecules of the present invention can be targeted to a widerange biological targets including, but not limited to, diseased cells(e.g., tumor cells) and tissues, healthy cells and tissues, nucleicacids (e.g., DNA, cDNA, RNA, mRNA, and siRNA), polypeptides (e.g.,enzymes, cell surface proteins, etc.), cell surface proteins, cellsurface receptors, cell surface polysaccharides, extracellular matrixproteins, intracellular proteins, and to microorganisms and otherpathogens (e.g., bacteria, fungi, mycoplasma, prions, viruses, and thelike).

A variety of targeting molecules are contemplated for use in associationwith the present compositions, including nucleic acids (e.g., RNA andDNA), polypeptides (e.g., receptor ligands, signal peptides, avidin,Protein A, antigen binding proteins, etc.), polysaccharides, biotin,hydrophobic groups, hydrophilic groups, drugs, and any organic moleculesthat bind to receptors. In some embodiments, the small molecules of thepresent invention are associated with multiple targeting molecules. Insome of these embodiments, the various targeting molecules are similar(e.g., monoclonal antibodies). In other embodiments, the targetingmolecules are dissimilar (e.g., antibodies with distinct idiotypes orisotypes, or antibodies and nucleic acids, etc.).

In some embodiments of the present invention, any number of cancer celltargeting groups are associated with the gossypol compounds. Thus, thegossypol compounds associated with targeting groups are specific fortargeting cancer cells (i.e., much more likely to attach to cancer cellsand not to healthy cells).

Utilization of more than one targeting molecule in a composition allowsmultiple biological targets to be targeted and/or provides the abilityto increase affinity for specific targets. Multiple targeting moleculesallow the compositions to be “stacked,” wherein a first composition istargeted to a first biological target, and a second composition istargeted to the first composition or to the first biological target. Anumber of exemplary targeting molecules and targeting methods aredescribe in more detail below.

A. General Targeting Molecules and Targeting Considerations

Various efficiency issues affect the administration of all drugs—and ofhighly cytotoxic drugs (e.g., anticancer drugs) in particular. One issueof particular importance is ensuring that the administered agents affectonly targeted cells (e.g., cancer cells), tissues, or organs. Thenonspecific or unintended delivery of highly cytotoxic agents tonontargeted cells can cause serious toxicity issues.

Numerous attempts have been made to devise drug targeting schemes toaddress the problems associated with nonspecific drug delivery. (Seee.g., K. N. Syrigos and A. A. Epenetos Anticancer Res., 19:606-614(1999); Y. J. Park et al., J. Controlled Release, 78:67-79 (2002); R. V.J. Chari, Adv. Drug Deliv. Rev., 31:89-104 (1998); and D. Putnam and J.Kopecek, Adv. Polymer Sci., 122:55-123 (1995)). Conjugating targetingmoieties such as antibodies and ligand peptides (e.g., RDG forendothelium cells) to drug molecules has been used to alleviate somecollateral toxicity issues associated with particular drugs. However,conjugating drugs to targeting moieties alone does not completely negatepotential side effects to nontargeted cells, since the drugs are usuallybioactive on their way to target cells. Advances in targetingmoiety-prodrug conjugates, which are inactive while traveling tospecific targeted tissues, have diminished some of these concerns. Abiotransformation, such as enzymatic cleavage, typically converts theprodrug into a biologically active molecule at the target site.

Accordingly, in some preferred embodiments, the present inventionprovides prodrug conjugates that are inactive until they reach theirtarget site, where they are subsequently converted into an activetherapeutic drug molecule. ADEPT and ATTEMPTS are two exemplary prodrugdelivery systems compatible with certain embodiments of the presentinvention. (See K. N. Syrigos and A. A. Epenetos, Anticancer Res.,19:606-614 (1999); K. D. Bagshawe, Brit. J. Cancer, 56:531-532 (1987);Y. J. Park et al., J. Controlled Release, 72:145-156 (2001); and Y. J.Park et al., J. Controlled Release, 78:67-79 (2002)).

The rapid clearance of some types of therapeutic agents, especiallywater-soluble low-molecular weight agents, from the subject'sbloodstream provides yet another obstacle to effective small moleculeadministration. Still other obstacles come from the rapid clearance(e.g., proteolytic degradation) or potential immunogenicity of theadministered agents.

In natural systems, clearance and other pharmacokinetic behaviors ofsmall molecules (e.g., drugs) in a subject are regulated by a series oftransport proteins. (See e.g., H. T. Nguyen, Clin. Chem. Lab. Anim.,(2nd Ed.) pp. 309-335 (1999); and G. J. Russell-Jones and D. H. Alpers,Pharm. Biotechnol., 12:493-520 (1999)). Thus, in preferred embodiments,the pharmacokinetics of agents are considered when testing anddeveloping potential therapeutics.

The rate of agent clearance in a subject is typically manageable. Forinstance, attaching (e.g., binding) the agent to a macromolecularcarrier normally prolongs circulation and retention times. Accordingly,some embodiments of the present invention provide small molecules (e.g.,gossypol compounds, drugs, or prodrugs) conjugated to polyethyleneglycol (PEG), or similar biopolymers, to decrease (prevent) themolecules' degradation and to improve its retention in the subject'sbloodstream. (See e.g., R. B. Greenwald et al., Critical Rev.Therapeutic Drug Carrier Syst., 17:101-161 (2000)). The ability of PEGto discourage protein-protein interactions can reduce the immunogenicityof many drugs.

Another issue affecting the administration of some therapeutic agents,and especially hydrophilic and macromolecular drugs such as peptides andnucleic acids, is that these agents have difficulty crossing intotargeted cellular membranes. Small (typically less than 1,000 Daltons)hydrophobic molecules are less susceptible to having difficultiesentering target cell membranes. Moreover, low molecular weight cytotoxicdrugs often localize more efficiently in normal tissues rather than intarget tissues such as tumors (K. Bosslet et al., Cancer Res.,58:1195-1201 (1998)) due to the high interstitial pressure andunfavorable blood flow properties within rapidly growing tumors (R. K.Jain, Int. J. Radiat. Biol., 60:85-100 (1991); and R. K. Jain and L. T.Baxter, Cancer Res., 48:7022-7032 (1998)).

Certain embodiments, especially those directed to delivering cytotoxicagents, utilize one or more of the following methods or compositions toaid delivery of the therapeutic compositions of the present invention:microinjection (See e.g., M. Foldvari and M. Mezei, J. Pharm. Sci.,80:1020-1028, (1991)); scrape loading (See e.g., P. L. McNeil et al., J.Cell Biol., 98:1556-1564 (1984)); electroporation (See e.g., R.Chakrabarti et al., J. Biol. Chem., 26:15494-15500 (1989)); liposomes(See e.g., M. Foldvari et al., J. Pharm. Sci., 80:1020-1028 (1991); andJ. N. Moreira et al., Biochim Biophys Acta., 515:167-176 (2001));nanocarriers such as water-soluble polymers (e.g., enhanced permeationand retention “EPR”, See e.g., H. Maeda et al., J. Controlled Release,65:271-284 (2000); H. Maeda et al., supra; and L. W. Seymour, Crit. Rev.Therapeu. Drug Carrier Systems, 9:135-187 (1992)); bacterial toxins (Seee.g., T. I. Prior et al., Biochemistry, 31:3555-3559 (1992); and H.Stenmark et al., J. Cell Biol., 113:1025-1032 (1991)); receptor-mediatedendocytosis and phagocytosis, including the tumor-activated prodrug(TAP) system (See e.g., R. V. J. Chari, Adv. Drug Deliv. Rev., 31:89-104(1998); I. Mellman, Annu. Rev. Cell Dev. Biol., 12:575-625 (1996); C. P.Leamon and P. S. Low, J. Biol. Chem., 267 (35):24966-24971 (1992); H.Ishihara et al., Pharm. Res., 7:542-546 (1990); S. K. Basu, Biochem.Pharmacol., 40:1941-1946 (1990); and G. Y. Wu and C. H. Wu,Biochemistry, 27:887-892 (1988)); other suitable compositions andmethods are known in the art.

B. Antibodies as Targeting Molecules

In some embodiments of the present invention, targeting moleculescomprise antigen binding proteins or immunoglobulins (antibodies).Immunoglobulins can be generated to allow for the targeting of antigensor immunogens (e.g., tumor, tissue, or pathogen specific antigens) onvarious biological targets (e.g., pathogens, tumor cells, normaltissue). Such immunoglobulins include, but are not limited to,polyclonal, monoclonal, chimeric, single chain, Fab fragments, and Fabexpression libraries.

Immunoglobulins (antibodies) are proteins generated by the immune systemto provide a specific molecule capable of complexing with an invadingmolecule commonly referred to as an antigen. Natural antibodies have twoidentical antigen-binding sites, both of which are specific to aparticular antigen. The antibody molecule recognizes the antigen bycomplexing its antigen-binding sites with areas of the antigen termedepitopes. The epitopes fit into the conformational architecture of theantigen-binding sites of the antibody, enabling the antibody to bind tothe antigen.

The immunoglobulin molecule is composed of two identical heavy and twoidentical light polypeptide chains, held together by interchaindisulfide bonds. Each individual light and heavy chain folds intoregions of about 110 amino acids, assuming a conserved three-dimensionalconformation. The light chain comprises one variable region (termedV_(L)) and one constant region (CL), while the heavy chain comprises onevariable region (V_(H)) and three constant regions (CH1, CH2 and CH3).Pairs of regions associate to form discrete structures. In particular,the light and heavy chain variable regions, V_(L) and V_(H), associateto form an “FV” area which contains the antigen-binding site.

The variable regions of both heavy and light chains show considerablevariability in structure and amino acid composition from one antibodymolecule to another, whereas the constant regions show littlevariability. Each antibody recognizes and binds an antigen through thebinding site defined by the association of the heavy and light chainvariable regions into an FV area. The light-chain variable region V_(L)and the heavy-chain variable region V_(H) of a particular antibodymolecule have specific amino acid sequences that allow theantigen-binding site to assume a conformation that binds to the antigenepitope recognized by that particular antibody.

Within the variable regions are “sub-regions” in which the amino acidsequence is extremely variable from one antibody to another. Three ofthese so-called “hypervariable” regions or “complementarity-determiningregions” (CDRs) are found in each of the light and heavy chains. Thethree CDRs from a light chain and the three CDRs from a correspondingheavy chain form the antigen-binding site.

Cleavage of naturally occurring antibody molecules with the proteolyticenzyme papain generates fragments that retain their antigen-bindingsite. These fragments, commonly known as Fabs (for Fragment, antigenbinding site) are composed of the C_(L), V_(L), C_(H)1 and V_(H) regionsof the antibody. In the Fab the light chain and the fragment of theheavy chain are covalently linked by a disulfide linkage.

Antibody fragments that contain the idiotype (antigen binding region) ofthe antibody molecule can be generated by known techniques. For example,such fragments include but are not limited to: the F(ab′)2 fragment thatcan be produced by pepsin digestion of the antibody molecule; the Fab′fragments that can be generated by reducing the disulfide bridges of theF(ab′)2 fragment, and the Fab fragments that can be generated bytreating the antibody molecule with papain and a reducing agent.

Various procedures known in the art are used for the production ofpolyclonal antibodies. For the production of antibody, various hostanimals can be immunized by injection with the peptide corresponding tothe desired epitope including, but not limited to, rabbits, mice, rats,sheep, goats, etc. In a preferred embodiment, the peptide is conjugatedto an immunogenic carrier (e.g., diphtheria toxoid, bovine serum albumin(BSA), or keyhole limpet hemocyanin (KLH)). Various adjuvants are usedto increase the immunological response, depending on the host species,including but not limited to Freund's (complete and incomplete), mineralgels such as aluminum hydroxide, surface active substances such aslysolecithin, pluronic polyols, polyanions, peptides, oil emulsions,keyhole limpet hemocyanins, dinitrophenol, and potentially useful humanadjuvants such as BCG (Bacille Calmette-Guerin) and Corynebacteriumparvum.

Monoclonal antibodies against target antigens (e.g., a cell surfaceprotein such as a receptor) are produced by a variety of techniquesincluding conventional monoclonal antibody methodologies such as thesomatic cell hybridization techniques of Kohler and Milstein, Nature,256:495 (1975). Although in some embodiments, somatic cell hybridizationprocedures are preferred, other techniques for producing monoclonalantibodies are contemplated as well (e.g., viral or oncogenictransformation of B lymphocytes).

For preparation of monoclonal antibodies, any technique that providesfor the production of antibody molecules by continuous cell lines inculture may be used (See e.g., Harlow and Lane, Antibodies: A LaboratoryManual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.).These include, but are not limited to, the hybridoma techniqueoriginally developed by Köhler and Milstein (Köhler and Milstein, Nature256:495-497 (1975)), as well as the trioma technique, the human B-cellhybridoma technique (See e.g., Kozbor et al., Immunol. Today 4:72(1983)), and the EBV-hybridoma technique to produce human monoclonalantibodies (Cole et al., in Monoclonal Antibodies and Cancer Therapy,Alan R. Liss, Inc., pp. 77-96 (1985)).

In an additional embodiment of the invention, monoclonal antibodies canbe produced in germ-free animals utilizing recent technology (See e.g.,PCT/US90/02545). According to the invention, human antibodies may beused and can be obtained by using human hybridomas (Cote et al., Proc.Natl. Acad. Sci. U.S.A., 80:2026-2030 (1983)) or by transforming human Bcells with EBV virus in vitro (Cole et al., in Monoclonal Antibodies andCancer Therapy, Alan R. Liss, pp. 77-96 (1985)).

In one embodiment, the preferred animal for preparing hybridomas is themouse. Hybridoma production in the mouse is a well-establishedprocedure. Immunization protocols and techniques for isolation ofimmunized splenocytes for fusion are known in the art. Fusion partners(e.g., murine myeloma cells) and fusion procedures are also known. Inother preferred embodiments, avian (e.g., chickens) species arepreferred for antibody production.

Human monoclonal antibodies (mAbs) directed against human proteins canbe generated using transgenic mice carrying the complete human immunesystem rather than the mouse system. Splenocytes from the transgenicmice are immunized with the antigen of interest which are used toproduce hybridomas that secrete human mAbs with specific affinities forepitopes from a human protein. (See e.g., Wood et al., WO 91/00906,Kucherlapati et al., WO 91/10741; Lonberg et al., WO 92/03918; Kay etal., WO 92/03917 (each of which is herein incorporated by reference inits entirety); N. Lonberg et al., Nature, 368:856-859 (1994); L. L.Green et al., Nature Genet., 7:13-21 (1994); S. L. Morrison et al.,Proc. Nat. Acad. Sci. U.S.A., 81:6851-6855 (1994); Bruggeman et al.,Immunol., 7:33-40 (1993); Tuaillon et al., Proc. Nat. Acad. Sci. U.S.A.,90:3720-3724 (1993); and Bruggernan et al. Eur. J. Immunol.,21:1323-1326 (1991)).

Monoclonal antibodies can also be generated by other methods known tothose skilled in the art of recombinant DNA technology. An alternativemethod, referred to as the “combinatorial antibody display” method, hasbeen developed to identify and isolate antibody fragments having aparticular antigen specificity, and can be utilized to producemonoclonal antibodies. (See e.g., Sastry et al., Proc. Nat. Acad. Sci.U.S.A., 86:5728 (1989); Huse et al., Science, 246:1275 (1989); andOrlandi et al., Proc. Nat. Acad. Sci. U.S.A., 86:3833 (1989)). Afterimmunizing an animal with an immunogen as described above, the antibodyrepertoire of the resulting B-cell pool is cloned. Methods are availablefor obtaining DNA sequences from the variable regions of a diversepopulation of immunoglobulin molecules using a mixture of oligomerprimers and PCR. For instance, mixed oligonucleotide primerscorresponding to the 5′ leader (signal peptide) sequences or framework 1(FR1) sequences, as well as primer to a conserved 3′ constant regionprimer can be used for PCR amplification of the heavy and light chainvariable regions from a number of murine antibodies. (See e.g. Larricket al., Biotechniques, 11:152-156 (1991)). A similar strategy can alsobeen used to amplify human heavy and light chain variable regions fromhuman antibodies (See e.g., Larrick et al., Methods: Companion toMethods in Enzymology, 2:106-110 (1991)).

In one embodiment, RNA is isolated from B lymphocytes, for example,peripheral blood cells, bone marrow, or spleen preparations, usingstandard protocols (e.g., U.S. Pat. No. 4,683,292 (incorporated hereinby reference in its entirety); Orlandi, et al., Proc. Nat. Acad. Sci.U.S.A., 86:3833-3837 (1989); Sastry et al., Proc. Nat. Acad. Sci.U.S.A., 86:5728-5732 (1989); and Huse et al., Science, 246:1275 (1989).First strand cDNA is synthesized using primers specific for the constantregion of the heavy chain(s) and each of the κ and λ light chains, aswell as primers for the signal sequence. Using variable region PCRprimers, the variable regions of both heavy and light chains areamplified, each alone or in combination, and ligated into appropriatevectors for further manipulation in generating the display packages.Oligonucleotide primers useful in amplification protocols may be uniqueor degenerate or incorporate inosine at degenerate positions.Restriction endonuclease recognition sequences may also be incorporatedinto the primers to allow for the cloning of the amplified fragment intoa vector in a predetermined reading frame for expression.

The V-gene library cloned from the immunization-derived antibodyrepertoire can be expressed by a population of display packages,preferably derived from filamentous phage, to form an antibody displaylibrary. Ideally, the display package comprises a system that allows thesampling of very large variegated antibody display libraries, rapidsorting after each affinity separation round, and easy isolation of theantibody gene from purified display packages. In addition tocommercially available kits for generating phage display libraries,examples of methods and reagents particularly amenable for use ingenerating a variegated antibody display library can be found in, forexample, U.S. Pat. No. 5,223,409; WO 92/18619; WO 91/17271; WO 92/20791;WO 92/15679; WO 93/01288; WO 92/01047; WO 92/09690; WO 90/02809 (each ofwhich is herein incorporated by reference in its entirety); Fuchs etal., Biol. Technology, 9:1370-1372 (1991); Hay et al., Hum. Antibod.Hybridomas, 3:81-85 (1992); Huse et al., Science, 46:1275-1281 (1989);Hawkins et al., J. Mol. Biol., 226:889-896 (1992); Clackson et al.,Nature, 352:624-628 (1991); Gram et al., Proc. Nat. Acad. Sci. U.S.A.,89:3576-3580 (1992); Garrad et al., Bio/Technolog, 2:1373-1377 (1991);Hoogenboom et al., Nuc. Acid Res., 19:4133-4137 (1991); and Barbas etal., Proc. Nat. Acad. Sci. U.S.A., 88:7978 (1991). In certainembodiments, the V region domains of heavy and light chains can beexpressed on the same polypeptide, joined by a flexible linker to form asingle-chain Fv fragment, and the scFV gene subsequently cloned into thedesired expression vector or phage genome.

As generally described in McCafferty et al., Nature, 348:552-554 (1990),complete V_(H) and V_(L) domains of an antibody, joined by a flexiblelinker (e.g., (Gly₄-Ser)₃) can be used to produce a single chainantibody which can render the display package separable based on antigenaffinity. Isolated scFV antibodies immunoreactive with the antigen cansubsequently be formulated into a pharmaceutical preparation for use inthe subject method.

According to the invention, techniques described for the production ofsingle chain antibodies (U.S. Pat. No. 4,946,778; herein incorporated byreference) can be adapted to produce specific single chain antibodies.An additional embodiment of the invention utilizes the techniquesdescribed for the construction of Fab expression libraries (Huse et al.,Science, 246:1275-1281 (1989)) to allow rapid and easy identification ofmonoclonal Fab fragments with the desired specificity.

Once displayed on the surface of a display package (e.g., filamentousphage), the antibody library is screened with the target antigen, orpeptide fragment thereof, to identify and isolate packages that expressan antibody having specificity for the target antigen. Nucleic acidencoding the selected antibody can be recovered from the display package(e.g. from the phage genome) and subcloned into other expression vectorsby standard recombinant DNA techniques.

Specific antibody molecules with high affinities for a surface proteincan be made according to methods known to those in the art, e.g.,methods involving screening of libraries. (See, e.g., U.S. Pat. No.5,233,409 and U.S. Pat. No. 5,403,484 (both incorporated herein byreference in their entireties)). Further, the methods of these librariescan be used in screens to obtain binding determinants that are mimeticsof the structural determinants of antibodies.

Generally, in the production of antibodies, screening for the desiredantibody can be accomplished by techniques known in the art (e.g.,radioimmunoassay, ELISA (enzyme-linked immunosorbant assay), “sandwich”immunoassays, immunoradiometric assays, gel diffusion precipitinreactions, immunodiffusion assays, in situ immunoassays (using colloidalgold, enzyme or radioisotope labels, for example), Western Blots,precipitation reactions, agglutination assays (e.g., gel agglutinationassays, hemagglutination assays, etc.), complement fixation assays,immunofluorescence assays, protein A assays, and immunoelectrophoresisassays, etc.).

In particular, the Fv binding surface of a particular antibody moleculeinteracts with its target ligand according to principles ofprotein-protein interactions, hence sequence data for V_(H) and V_(L)(the latter of which may be of the κ or λ chain type) is the basis forprotein engineering techniques known to those with skill in the art.Details of the protein surface that comprises the binding determinantscan be obtained from antibody sequence in formation, by a modelingprocedure using previously determined three-dimensional structures fromother antibodies obtained from NMR studies or crystallographic data.

In one embodiment, a variegated peptide library is expressed by apopulation of display packages to form a peptide display library.Ideally, the display package comprises a system that allows the samplingof very large variegated peptide display libraries, rapid sorting aftereach affinity separation round, and easy isolation of thepeptide-encoding gene from purified display packages. Peptide displaylibraries can be in, e.g., prokaryotic organisms and viruses, which canbe amplified quickly, are relatively easy to manipulate, and whichallows the creation of a large number of clones. Preferred displaypackages include, for example, vegetative bacterial cells, bacterialspores, and most preferably, bacterial viruses (especially DNA viruses).However, the present invention also contemplates the use of eukaryoticcells, including yeast and their spores, as potential display packages.Phage display libraries are known in the art.

Other techniques include affinity chromatography with an appropriate“receptor,” e.g., a target antigen, followed by identification of theisolated binding agents or ligands by conventional techniques (e.g.,mass spectrometry and NMR). Preferably, the soluble receptor isconjugated to a label (e.g., fluorophores, colorimetric enzymes,radioisotopes, or luminescent compounds) that can be detected toindicate ligand binding. Alternatively, immobilized compounds can beselectively released and allowed to diffuse through a membrane tointeract with a receptor.

Combinatorial libraries of compounds can also be synthesized with “tags”to encode the identity of each member of the library. (See e.g., W. C.Still et al., WO 94/08051, incorporated herein by reference in itsentirety). In general, this method features the use of inert but readilydetectable tags that are attached to the solid support or to thecompounds. When an active compound is detected, the identity of thecompound is determined by identification of the unique accompanying tag.This tagging method permits the synthesis of large libraries ofcompounds that can be identified at very low levels among the total setof all compounds in the library.

The term modified antibody is also intended to include antibodies, suchas monoclonal antibodies, chimeric antibodies, and humanized antibodies,which have been modified by, for example, deleting, adding, orsubstituting portions of the antibody. For example, an antibody can bemodified by deleting the hinge region, thus generating a monovalentantibody. Any modification is within the scope of the invention so longas the antibody has at least one antigen binding region specific.

Chimeric mouse-human monoclonal antibodies can be produced byrecombinant DNA techniques known in the art. For example, a geneencoding the Fc constant region of a murine (or other species)monoclonal antibody molecule is digested with restriction enzymes toremove the region encoding the murine Fc, and the equivalent portion ofa gene encoding a human Fc constant region is substituted. (See e.g.,Robinson et al., PCT/US86/02269; European Patent Application 184,187;European Patent Application 171,496; European Patent Application173,494; WO 86/01533; U.S. Pat. No. 4,816,567; European PatentApplication 125,023 (each of which is herein incorporated by referencein its entirety) Better et al., Science, 240:1041-1043 (1988); Liu etal., Proc. Nat. Acad. Sci. U.S.A., 84:3439-3443 (1987); Liu et al., J.Immunol., 139:3521-3526 (1987); Sun et al., Proc. Nat. Acad. Sci.U.S.A., 84:214-218 (1987); Nishimura et al., Canc. Res., 47:999-1005(1987); Wood et al., Nature, 314:446-449 (1985); and Shaw et al., J.Natl. Cancer Inst., 80:1553-1559 (1988)).

The chimeric antibody can be further humanized by replacing sequences ofthe Fv variable region which are not directly involved in antigenbinding with equivalent sequences from human Fv variable regions.General reviews of humanized chimeric antibodies are provided by S. L.Morrison, Science, 229:1202-1207 (1985) and by Oi et al., Bio.Techniques, 4:214 (1986). Those methods include isolating, manipulating,and expressing the nucleic acid sequences that encode all or part ofimmunoglobulin Fv variable regions from at least one of a heavy or lightchain. Sources of such nucleic acids are known and, for example, may beobtained from 7E3, an anti-GPIIbIIIa antibody producing hybridoma. Therecombinant DNA encoding the chimeric antibody, or fragment thereof, isthen cloned into an appropriate expression vector.

Suitable humanized antibodies can alternatively be produced by CDRsubstitution (e.g., U.S. Pat. No. 5,225,539 (incorporated herein byreference in its entirety); Jones et al., Nature, 321:552-525 (1986);Verhoeyan et al., Science, 239:1534 (1988); and Beidler et al., J.Immunol., 141:4053 (1988)). All of the CDRs of a particular humanantibody may be replaced with at least a portion of a non-human CDR oronly some of the CDRs may be replaced with non-human CDRs. It is onlynecessary to replace the number of CDRs required for binding of thehumanized antibody to the Fc receptor.

An antibody is humanized by any method that is capable of replacing atleast a portion of a CDR of a human antibody with a CDR derived from anon-human antibody. The human CDRs may be replaced with non-human CDRsusing oligonucleotide site-directed mutagenesis.

Also within the scope of the invention are chimeric and humanizedantibodies in which specific amino acids have been substituted, deletedor added. In particular, preferred humanized antibodies have amino acidsubstitutions in the framework region, such as to improve binding to theantigen. For example, in a humanized antibody having mouse CDRs, aminoacids located in the human framework region can be replaced with theamino acids located at the corresponding positions in the mouseantibody. Such substitutions are known to improve binding of humanizedantibodies to the antigen in some instances.

In preferred embodiments, the fusion proteins include a monoclonalantibody subunit (e.g., a human, murine, or bovine), or a fragmentthereof, (e.g., an antigen binding fragment thereof). The monoclonalantibody subunit or antigen binding fragment thereof can be a singlechain polypeptide, a dimer of a heavy chain and a light chain, atetramer of two heavy and two light chains, or a pentamer (e.g., IgM).IgM is a pentamer of five monomer units held together by disulfide bondslinking their carboxyl-terminal (Cμ4/Cμ4) domains and Cμ3/Cμ3 domains.The pentameric structure of IgM provides 10 antigen-binding sites, thusserum IgM has a higher valency than other types of antibody isotypes.With its high valency, pentameric IgM is more efficient than otherantibody isotypes at binding multidimensional antigens (e.g., viralparticles and red blood cells. However, due to its large pentamericstructure, IgM does not diffuse well and is usually found in lowconcentrations in intercellular tissue fluids. The J chain of IgM allowsthe molecule to bind to receptors on secretory cells, which transportthe molecule across epithelial linings to the external secretions thatbathe the mucosal surfaces. In some embodiments, the present inventiontakes advantage of the low diffusion rate of pentameric IgM to helpconcentrate the fusion proteins of the present invention at a site ofinterest.

In some preferred embodiments, the monoclonal antibody is a murineantibody or a fragment thereof. In other preferred embodiments, themonoclonal antibody is a bovine antibody or a fragment thereof. Forexample, the murine antibody can be produced by a hybridoma thatincludes a 13 cell obtained from a transgenic mouse having a genomecomprising a heavy chain transgene and a light chain transgene fused toan immortalized cell. The antibodies can be of the various isotypes,including, IgG (e.g., IgG1, IgG2, IgG3, IgG4), IgM, IgA1, IgA2, IgAsec,IgD, or IgE. In some preferred embodiments, the antibody is an IgGisotype. In other preferred embodiments, the antibody is an IgM isotype.The antibodies can be full-length (e.g., an IgG1, IgG2, IgG3, or IgG4antibody) or can include only an antigen-binding portion (e.g., a Fab,F(ab′)2, Fv or a single chain Fv fragment).

In preferred embodiments, the immunoglobulin subunit of the fusionproteins is a recombinant antibody (e.g., a chimeric or a humanizedantibody), a subunit or an antigen binding fragment thereof (e.g., has avariable region, or at least a complementarity determining region(CDR)).

In preferred embodiments, the immunoglobulin subunit of the fusionprotein is monovalent (e.g., includes one pair of heavy and lightchains, or antigen binding portions thereof). In other embodiments, theimmunoglobulin subunit of the fusion protein is divalent (e.g., includestwo pairs of heavy and light chains, or antigen binding portionsthereof). In preferred embodiments, the transgenic fusion proteinsinclude an immunoglobulin heavy chain or a fragment thereof (e.g., anantigen binding fragment thereof).

In preferred embodiments of the present invention, the targeting agentis an antibody or antigen binding fragment of an antibody (e.g., Fabunits). For example, a well-studied antigen found on the surface of manycancers (including breast HER2 tumors) is glycoprotein p185, which isexclusively expressed in malignant cells (Press et al., Oncogene 5:953(1990)). Recombinant humanized anti-HER2 monoclonal antibodies(rhuMabHER2) have even been shown to inhibit the growth of HER2overexpressing breast cancer cells, and are being evaluated (inconjunction with conventional chemotherapeutics) in phase III clinicaltrials for the treatment of advanced breast cancer (Pegrarn et al.,Proc. Am. Soc. Clin. Oncol., 14:106 (1995)). Park et al. have attachedFab fragments of rhuMabHER2 to small unilamellar liposomes, which thencan be loaded with the chemotherapeutic doxorubicin (dox) and targetedto HER2 overexpressing tumor xenografts (Park et al., Cancer Lett.,118:153 (1997) and Kirpotin et al., Biochem., 36:66 (1997)). Thesedox-loaded “immunoliposomes” showed increased cytotoxicity againsttumors compared to corresponding non-targeted dox-loaded liposomes orfree dox, and decreased systemic toxicity compared to free dox.

In some preferred embodiments, the antibodies recognize tumor specificepitopes (e.g., TAG-72 (Kjeldsen et al., Cancer Res., 48:2214-2220(1988); U.S. Pat. Nos. 5,892,020; 5,892,019; and 5,512,443); humancarcinoma antigen (U.S. Pat. Nos. 5,693,763; 5,545,530; and 5,808,005);TP1 and TP3 antigens from osteocarcinoma cells (U.S. Pat. No.5,855,866); Thomsen-Friedenreich (TF) antigen from adenocarcinoma cells(U.S. Pat. No. 5,110,911); “KC-4 antigen” from human prostrateadenocarcinoma (U.S. Pat. Nos. 4,708,930 and 4,743,543); a humancolorectal cancer antigen (U.S. Pat. No. 4,921,789); CA125 antigen fromcystadenocarcinoma (U.S. Pat. No. 4,921,790); DF3 antigen from humanbreast carcinoma (U.S. Pat. Nos. 4,963,484 and 5,053,489); a humanbreast tumor antigen (U.S. Pat. No. 4,939,240); p97 antigen of humanmelanoma (U.S. Pat. No. 4,918,164); carcinoma or orosomucoid-relatedantigen (CORA) (U.S. Pat. No. 4,914,021); a human pulmonary carcinomaantigen that reacts with human squamous cell lung carcinoma but not withhuman small cell lung carcinoma (U.S. Pat. No. 4,892,935); T and Tnhaptens in glycoproteins of human breast carcinoma (Springer et al.,Carbohydr. Res., 178:271-292 (1988)), MSA breast carcinoma glycoprotein(Tjandra et al., Br. J. Surg., 75:811-817 (1988)); MFGM breast carcinomaantigen (Ishida et al., Tumor Biol., 10:12-22 (1989)); DU-PAN-2pancreatic carcinoma antigen (Lan et al., Cancer Res., 45:305-310(1985)); CA125 ovarian carcinoma antigen (Hanisch et al., Carbohydr.Res., 178:29-47 (1988)); YH206 lung carcinoma antigen (Hinoda et al.,Cancer J., 42:653-658 (1988)). Each of the foregoing references isspecifically incorporated herein by reference.

For breast cancer, the cell surface may be targeted with mammastatin,folic acid, EGF, FGF, and antibodies (or antibody fragments) to thetumor-associated antigens MUC1, cMet receptor and CD56 (NCAM).

A very flexible method to identify and select appropriate peptidetargeting groups is the phage display technique (See e.g., Cortese etal., Curr. Opin. Biotechol., 6:73 (1995)), which can be convenientlycarried out using commercially available kits. The phage displayprocedure produces a large and diverse combinatorial library of peptidesattached to the surface of phage, which are screened against immobilizedsurface receptors for tight binding. After the tight-binding, viralconstructs are isolated and sequenced to identify the peptide sequences.The cycle is repeated using the best peptides as starting points for thenext peptide library. Eventually, suitably high-affinity peptides areidentified and then screened for biocompatibility and targetspecificity. In this way, it is possible to produce peptides conjugatedto dendrimers, producing multivalent conjugates with high specificityand affinity for the target cell receptors (e.g., tumor cell receptors)or other desired targets. In some embodiments, the gossypol compounds orother therapeutic agents are associated with dendrimers (e.g., PAMAM),or liposomes, or other carriers. Those skilled in the art will be ableto readily design dendrimer gossypol compound molecules that takeadvantage of the multivalent structure of dendrimers.

Related to the targeting approaches described above is the“pretargeting” approach (See e.g., Goodwin and Meares, Cancer (suppl.),80:2675 (1997)). An example of this strategy involves initial treatmentof the patient with conjugates of tumor-specific monoclonal antibodiesand streptavidin. Remaining soluble conjugate is removed from thebloodstream with an appropriate biotinylated clearing agent. When thetumor-localized conjugate is all that remains, a gossypol-linked,biotinylated agent is introduced, which in turn localizes at the tumorsites by the strong and specific biotin-streptavidin interaction.

In other preferred embodiments, the antibodies recognize specificpathogens (e.g., Legionella peomophilia, Mycobacterium tuberculosis,Clostridium tetani, Hemophilus influenzae, Neisseria gonorrhoeae,Treponema pallidum, Bacillus anthracis, Vibrio cholerae, Borreliaburgdorferi, Comebacterium diphtheria, Staphylococcus aureus, humanpapilloma virus, human immunodeficiency virus, rubella virus, poliovirus, and the like).

C. Peptides as Targeting Molecules

In some preferred embodiments, targeting molecules comprise peptidesthat bind specifically to tumor blood vessels. (See e.g., Arap et al.,Science, 279:377-80 (1998)). These peptides include, but are not limitedto, peptides containing the RGD (Arg-Gly-Asp) motif (e.g., CDCRGDCFC;SEQ ID NO:4), the NGR (Asn-Gly-Arg) motif (e.g., CNGRCVSGCAGRC; SEQ IDNO:5), and the GSL (Gly-Ser-Leu; SEQ ID NO:6) motif. These peptides andconjugates containing these peptides selectively bind to various tumors,including, but not limited to, breast carcinomas, Kaposi's sarcoma, andmelanoma. It is not intended that the present invention be limited toany particular mechanism of action. Indeed, an understanding of themechanism is not necessary to make and use the present invention.However, it is believed that these peptides are ligands for integrinsand growth factor receptors that are absent or barely detectable inestablished blood vessels. In some preferred embodiments, the peptide ispreferably produced using chemical synthesis methods. For example,peptides can be synthesized by solid phase techniques, cleaved from theresin, and purified by preparative high performance liquidchromatography. (See e.g., Creighton (1983) Proteins Structures andMolecular Principles, W.H. Freeman and Co, New York, N.Y.). In otherembodiments, the composition of the synthetic peptides is confirmed byamino acid analysis or sequencing.

In some preferred embodiments, targeting molecules comprise peptidesthat specifically bind to glioma cells. (See e.g., Debinski et al.,Nature Biotech., 16:449-53 (1998); Debinski et al., J. Biol. Chem.,270(28):16775-80 (1995); and Debinski et al., J. Biol. Chem.,271(37):22428-33 (1996)). In some embodiments, the present inventioncontemplates using drug delivery compositions comprising IL13, or one ofits variants, so that the drug delivery compositions bind to IL13binding sites in glioma cells.

Human high-grade gliomas are uniquely enriched in IL13 binding sites.Many of the established brain tumor cell lines, primarily malignantgliomas, over-express hIL13 binding sites. Human malignant glioma celllines express a high number, up to 30,000, of binding sites for hIL13per cell. Of interest, glioblastoma multiforme (GBM) explant cellsshowed an extraordinarily high number of hIL13 binding sites, up to500,000 per cell. The binding of hL13 is not neutralized by hIL4 on anarray of established human glioma cell lines that includes U-251 MG,U-373 MG, DBTRG MG, Hs-683, U-87 MG, SNB-19, and A-172 cells. hIL13 canbe engineered to increase its specific targeting of high-grade gliomas.The pattern for IL13 and IL4R sharing on normal cells requires IL13 tobind hIL4R. This is confirmed by the fact that hIL13 binding is alwaysfully competed by hIL4. The recently proposed model for this hIL13Rsuggests that the shared hIL13/4R is heterodimeric. This scenario wouldimply that hIL13 may contain at least two receptor-binding sites, eachrecognizing a respective subunit of the receptor. The engineered hIL13variants (e.g., hIL13.E13K or hIL13.E13Y) are deprived of cell signalingabilities. This is desirable because interaction with physiologicalsystems contributes prominently to the dose-limiting toxicity of somebiological therapeutics (e.g., cytokines). Significantly, the moleculeof hIL13 appears not to be sensitive to a variety of geneticallyengineered modifications and these variants can be produced in largequantities. It is thus possible to divert the molecule of hIL13 from itsphysiological receptor and make it a non-signaling compound, while thediscovery of the expression of IL13 receptors on the surface of all ofthe malignancies of glial origin provides a novel strategy for theaccumulation and retention of drug delivery compositions within CNScancers. The high-grade glioma (HGG)-associated receptor for IL13 usedin the present affinity toward the HGG-associated receptor remainsintact or is increased. Such forms of IL13 can serve as rationallydesigned vectors for variety of imaging and therapeutic approaches ofHGG.

Given the typically grim prognosis following the identification of anintracranial malignancy, any strategy for the pre-, intra- orpost-operative identification and removal of cancer cells is asignificant improvement. In some embodiments, nucleic acids encodingIL13 fragments, fusion proteins or functional equivalents or variants(e.g., hIL13.E13K or hIL13.E13Y) thereof are cloned into an appropriateexpression vector, expressed and purified (e.g., preferably as describedin Debinski et al., Nature Biotech., 16:449-53 (1998); Debinski et al.,J. Biol. Chem., 270(28):16775-80 (1995); and Debinski et al., J. Biol.Chem., 271(37):22428-33 (1996)). In other embodiments of the presentinvention, vectors include, but are not limited to, chromosomal,nonchromosomal and synthetic DNA sequences, e.g., derivatives of SV40;bacterial plasmids; phage DNA; baculovirus; yeast plasmids; vectorsderived from combinations of plasmids and phage DNA, viral DNA such asvaccinia, adenovirus, fowl pox virus, and pseudorabies. Large numbers ofsuitable vectors are known to those of skill in the art, and arecommercially available. Such vectors include, but are not limited to,the following vectors: 1) Bacterial—pQE70: pQE60; pQE-9 (Qiagen, Inc.,Valencia, Calif.); pBS; pD10; phagescript; psiX174; pbluescript SK;pBSKS; pNH8A; pNH16a; pNH18A; pNH46A (Stratagene, Inc., La Jolla,Calif.); ptrc99a; pKK223-3; pKK233-3; pDR540; pRIT5 (Pharmacia, Peapack,N.J.); and 2) Eukaryotic—pWLNEO; pSV2CAT; pOG44; PXT1; pSG (Stratagene);pSVK3; pBPV; pMSG; and pSVL (Pharmacia). Any other plasmid or vector canbe used as long as they are replicable and viable in the host. In somepreferred embodiments of the present invention, mammalian expressionvectors comprise an origin of replication, a suitable promoter andenhancer, and any necessary ribosome binding sites, polyadenylationsite, splice donor and acceptor sites, transcriptional terminationsequences, and 5′ flanking nontranscribed sequences. In otherembodiments, DNA sequences derived from the SV40 splice, andpolyadenylation sites are used to provide the required nontranscribedgenetic elements.

In other embodiments, the IL13 peptide or variant thereof is expressedin a host cell. In some embodiments of the present invention, the hostcell is a higher eukaryotic cell (e.g., a mammalian or insect cell). Inother embodiments of the present invention, the host cell is a lowereukaryotic cell (e.g., a yeast cell). In still other embodiments of thepresent invention, the host cell can be a prokaryotic cell (e.g., abacterial cell). Specific examples of host cells include, but are notlimited to, Escherichia coli, Salmonella typhimurium, Bacillus subtilis,and various species within the genera Pseudomonas, Streptomyces, andStaphylococcus, as well as Saccharomyces cerevisiae, Schizosaccharomycespombe, Drosophila S2 cells, Spodoptera Sf9 cells, Chinese Hamster Ovary(CHO) cells, COS-7 lines of monkey kidney fibroblasts, (Gluzman, Cell,23:175 (1981)), C127, 3T3, HeLa and BHK cell lines.

In some embodiments of the present invention, IL13 or variants thereofare recovered or purified from recombinant cell cultures by methodsincluding, but not limited to, ammonium sulfate or ethanolprecipitation, acid extraction, anion or cation exchange chromatography,phosphocellulose chromatography, hydrophobic interaction chromatography,affinity chromatography, hydroxylapatite chromatography and lectinchromatography. In other embodiments of the present invention, proteinrefolding steps are used, as necessary, in completing configuration ofthe mature protein. In still other embodiments of the present invention,high performance liquid chromatography (HPLC) is employed for finalpurification steps.

Some embodiments of the present invention provide polynucleotides havingthe coding sequence fused in frame to a marker sequence that allows forpurification of the polypeptide of the present invention. A non-limitingexample of a marker sequence is a hexahistidine tag that is supplied bya vector, preferably a pQE-9 vector, that provides for purification ofthe polypeptide fused to the marker in the case of a bacterial host, or,for example, the marker sequence may be a hemagglutinin (HA) tag when amammalian host (e.g. COS-7 cells) is used. The HA tag corresponds to anepitope derived from the influenza hemagglutinin protein (Wilson, etal., Cell, 37:767 (1984)).

D. Signal Peptide as Targeting Molecules

In some embodiments of the present invention, the targeting moleculescomprise signal peptides. These peptides are chemically synthesized orcloned, expressed and purified as described above. Signal peptides canassist the chemical address tags of the present invention target thedrug delivery composition (or a portion thereof) to discrete regionswithin a cell. In some of these embodiments, the signal peptide ispreferably:NH-Met-Leu-Ser-Leu-Arg-Gln-Ser-Ile-Arg-Phe-Phe-Lys-Pro-Ala-Thr-Arg-Thr-Leu-COOH(SEQ ID NO:7). The present invention is not limited to any particularmechanism, and an understanding of mechanisms is not necessary to makeand use the present invention, however, it is contemplated that thepeptide of SEQ ID NO:7 forms an amphipathic helix that associates withmitochondrial membrane protein import sites. This association allowspeptide complexes to attach to mitochondrial membranes. It is unlikelythat the complex is internalized, since there are few pores of nanometersize on intact mitochondria. In still other embodiments, the followingnuclear localization signal is utilized:NH-Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val-COOH (SEQ ID NO:8).

E. Nucleic Acids as Targeting Molecules

In some embodiments of the present invention, the targeting moleculescomprise nucleic acids (e.g., RNA or DNA). In some embodiments, thesenucleic acid moieties are designed to hybridize (by base pairing) to aparticular nucleic acid (e.g., chromosomal DNA, mRNA, or ribosomal RNA)sequence in target cells and tissues. Exemplary nucleic acids include,but are not limited to, those coding for reverse transcriptase, REV andTAT proteins of HIV (Tuerk et al., Gene, 137(1):33-9 (1993)); humannerve growth factor (Binkley et al., Nuc. Acids Res., 23(16):3198-205(1995)); and vascular endothelial growth factor (Jellinek et al.,Biochem., 83(34):10450-6 (1994)). In other embodiments, the targetingmolecules bind ligands or biological targets directly. In someembodiments, suitable nucleic acids that bind ligands are identifiedusing the SELEX procedure (U.S. Pat. Nos. 5,475,096; 5,270,163; WO97/38134; WO 98/33941; and WO 99/07724; all of which are hereinincorporated by reference), although many additional methods are knownin the art and are suitable in certain embodiments of the presentinvention.

F. Other Cellular Targeting Molecules

The targeting molecules of the present compositions may recognize avariety of epitopes on biological targets (e.g., pathogens, tumor cells,normal tissues). In some embodiments, cellular level targeting moietiesare incorporated to recognize, target, or detect a variety of pathogenicorganisms including, but not limited to, tumor specific antigens (e.g.,carcinoembryonic antigen, prostate specific antigen, tyrosinase, ras, asialyl lewis antigen, erb, MAGE-1, MAGE-3, BAGE, MN, gp100, gp75, p97,proteinase 3, a mucin, CD81, CID9, CD63, CD53, CD38, CO-029, CA125, GD2,GM2 and O-acetyl GD3, M-TAA, M-fetal or M-urinary). Alternatively, thetargeting molecules may be a tumor suppressor, a cytokine, a chemokine,a tumor specific receptor ligand, a receptor, an inducer of apoptosis,or a differentiating agent.

Tumor suppressor proteins contemplated for targeting include, but arenot limited to, p16, p21, p27, p53, p73, Rb, Wilms tumor (WT-1), DCC,neurofibromatosis type 1 (NF-1), von Hippel-Lindau (VHL) disease tumorsuppressor, Maspin, Brush-1, BRCA-1, BRCA-2, the multiple tumorsuppressor (MTS), gp95/p97 antigen of human melanoma, renal cellcarcinoma-associated G250 antigen, KS 1/4 pan-carcinoma antigen, ovariancarcinoma antigen (CA125), prostate specific antigen, melanoma antigengp75, CD9, CD63, CD53, CD37, R2, CD81, CO029, TI-1, L6 and SAS. Ofcourse, these are merely exemplary tumor suppressors. It is envisionedthat the present invention may be used in conjunction with any otheragents that are or become known to those of skill in the art as a tumorsuppressor or tumor marker.

In preferred embodiments of the present invention, the compositions aretargeted to factors expressed by oncogenes. These include, but are notlimited to, tyrosine kinases, both membrane-associated and cytoplasmicforms, such as members of the Src family, serine/threonine kinases, suchas Mos, growth factor receptors, such as platelet derived growth factor(PDGF), SMALL GTPases (G proteins) including the ras family,cyclin-dependent protein kinases (cdk), members of the myc family,including c-myc, N-myc, and L-myc and bcl-2 and family members.

Receptors and their related ligands that find use in the context ofcertain embodiments of the present invention include, but are notlimited to, the folate receptor, adrenergic receptor, growth hormonereceptor, luteinizing hormone receptor, estrogen receptor, epidermalgrowth factor receptor, fibroblast growth factor receptor, and the like.

Hormones and their receptors that find use in the cellular leveltargeting aspects of the present invention include, but are not limitedto, growth hormone, prolactin, placental lactogen, luteinizing hormone,follicle-stimulating hormone, chorionic gonadotropin,thyroid-stimulating hormone, leptin, adrenocorticotropin (ACTH),angiotensin I, angiotensin II, α-endorphin, α-melanocyte stimulatinghormone (α-MSH), cholecystokinin, endothelin I, galanin, gastricinhibitory peptide (GIP), glucagon, insulin, amylin, lipotropins, GLP-1(7-37) neurophysins, mammastatin, and somatostatin.

In addition, the present invention contemplates that vitamins (both fatsoluble and non-fat soluble vitamins) can be used as targeting moleculesto target biological targets (e.g., cells) that have receptors for, orotherwise take up, these vitamins. Particularly preferred for thisaspect of the invention are the fat soluble vitamins D, E, and A, andanalogues thereof, and the water soluble vitamin C.

IX. Pharmaceutical Formulations, Administration Routes, and DosingConsiderations

The present invention provides pharmaceutical compositions which maycomprise at least one gossypol compound, and in preferred embodiments,at least one conventional anticancer agent. The gossypol compounds andanticancer agents may be administered in any sterile, biocompatiblepharmaceutical carrier, including, but not limited to, saline, bufferedsaline, dextrose, and water. In some embodiments, the pharmaceuticalcompositions of the present invention may contain one agent (e.g., agossypol compound). In other embodiments, the pharmaceuticalcompositions contain a mixture of at least two agents (e.g., a gossypolcompound and one or more conventional anticancer agents). In stillfurther embodiments, the pharmaceutical compositions of the presentinvention contain at least two agents (e.g., gossypol compounds and oneor more conventional anticancer agents) that are administered to apatient under one or more of the following conditions: at differentperiodicities, at different durations, at different concentrations, bydifferent administration routes, etc. In some embodiments, the gossypolcompound is administered prior to the anticancer agent, e.g., 0.5, 1, 23, 4, 5, 10, 12, or 18 hours, 1, 2, 3, 4, 5, or 6 days, 1, 2, 3, or 4weeks prior to the administration of the anticancer agent. In someembodiments, the gossypol compound is administered after the anticanceragent, e.g., 0.5, 1, 2 3, 4, 5, 10, 12, or 18 hours, 1, 2, 3, 4, 5, or 6days, 1, 2, 3, or 4 weeks after the administration of the anticanceragent. In some embodiments, the gossypol compound and the anticanceragent are administered concurrently but on different schedules, e.g.,the gossypol compound is administered daily while the anticancer agentis administered once a week, once every two weeks, once every threeweeks, or once every four weeks. In other embodiments, the gossypolcompound is administered once a week while the anticancer agent isadministered daily, once a week, once every two weeks, once every threeweeks, or once every four weeks.

The compositions and methods of the present invention find use intreating diseases or in altering physiological states that arecharacterized by the overexpression of one or more Bcl-2 family proteins(e.g., Bcl-2, Bcl-X_(L), Mcl-1, A1/BFL-1, and BOO-DIVA, etc.). Theinvention further provides methods for inducing apoptosis in cells byantagonizing the anti-apoptotic affects of some Bcl-2 family proteinsincluding, but not limited to, Bcl-2, Bcl-X_(L), Mcl-1, A1/BFL-1, andBOO-DIVA.

Depending on the condition being treated, preferred embodiments of thepresent pharmaceutical compositions are formulated and administeredsystemically or locally. Techniques for formulation and administrationcan be found in the latest edition of “Remington's PharmaceuticalSciences” (Mack Publishing Co, Easton Pa.). Exemplary pharmaceuticalformulations and methods of producing pharmaceuticals are described inU.S. 20030211046A1; U.S. 20030004182A1; U.S. 2002060356384; U.S.20020015728A1; U.S. Pat. No. 6,511,660; U.S. Pat. No. 6,406,745; U.S.Pat. No. 6,346,269; U.S. Pat. No. 6,039,977; U.S. Pat. No. 5,858,408;U.S. Pat. No. 5,631,023; U.S. Pat. No. 5,476,667; U.S. Pat. No.5,044,091; U.S. Pat. No. 4,867,970; and WO 0028969A2 each of which isincorporated herein by reference in its entirety). Suitable routes may,for example, include oral or transmucosal administration as well asparenteral delivery (e.g., intramuscular, subcutaneous, intramedullary,intrathecal, intraventricular, intravenous, intraperitoneal, orintranasal administration).

The present invention contemplates administering gossypol compounds and,in some embodiments, one or more conventional anticancer agents, inaccordance with acceptable pharmaceutical delivery methods andpreparation techniques. For example, gossypol compounds and suitableanticancer agents can be administered to a subject intravenously in apharmaceutically acceptable carrier such as physiological saline.Standard methods for intracellular delivery of pharmaceutical agents arecontemplated (e.g. delivery via liposome). Such methods are well knownto those of ordinary skill in the art.

In some embodiments, the formulations of the present invention areuseful for parenteral administration (e.g., intravenous, subcutaneous,intramuscular, intramedullary, and intraperitoneal). Therapeuticco-administration of some contemplated anticancer agents (e.g.,therapeutic polypeptides) can also be accomplished using gene therapyreagents and techniques.

In some embodiments of the present invention, gossypol compounds areadministered to a subject alone, or in combination with one or moreconventional anticancer agents (e.g., nucleotide sequences, drugs,hormones, etc.) or in pharmaceutical compositions where the componentsare optionally mixed with excipient(s) or other pharmaceuticallyacceptable carriers. In preferred embodiments of the present invention,pharmaceutically acceptable carriers are biologically inert. Inpreferred embodiments, the pharmaceutical compositions of the presentinvention are formulated using pharmaceutically acceptable carriers wellknown in the art in dosages suitable for oral administration. Suchcarriers enable the pharmaceutical compositions to be formulated astablets, pills, capsules, dragees, liquids, gels, syrups, slurries,solutions, suspensions and the like, for respective oral or nasalingestion by a subject. In preferred embodiments, the gossypol compoundsare administered orally to a subject.

Pharmaceutical preparations for oral use can be obtained by combiningthe active compounds (e.g., gossypol compounds) with solid excipients,optionally grinding the resulting mixture, and processing the mixtureinto granules, after adding suitable auxiliaries, if desired, to obtaintablets or dragee cores. Suitable excipients are carbohydrate or proteinfillers such as sugars, including lactose, sucrose, mannitol, orsorbitol; starch from corn, wheat, rice, potato, etc.; cellulose such asmethyl cellulose, hydroxypropylmethyl-cellulose, or sodiumcarboxymethylcellulose; gums including arabic and tragacanth; andproteins such as gelatin and collagen. If desired, disintegrating orsolubilizing agents may be added, such as the cross-linked polyvinylpyrrolidone, agar, alginic acid or a salt thereof such as sodiumalginate.

For injection, the pharmaceutical compositions of the invention may beformulated in aqueous solutions, preferably in physiologicallycompatible buffers such as Hanks' solution, Ringer's solution, orphysiologically buffered saline. For tissue or cellular administration,penetrants appropriate to the particular barrier to be permeated areused. Such penetrants are known to those skilled in the art.

Pharmaceutical compositions suitable for use in the present inventioninclude compositions wherein the active ingredients are contained in aneffective amount to achieve the intended purpose. For example, aneffective amount of a gossypol compound may be that amount that inducesapoptosis in a cell or tissue having elevated levels of a Bcl-2 familyprotein as compared to normal nonpathological cells or tissues. Thedetermination of an effective amount of an agent is well within theskills of those in the pharmacological arts, especially in view of thedisclosure provided herein.

In addition to the active ingredients, preferred pharmaceuticalcompositions may contain suitable pharmaceutically acceptable carrierscomprising excipients and auxiliaries that facilitate processing of theactive compounds into pharmaceutically useful forms.

The pharmaceutical compositions of the present invention may bemanufactured using any acceptable techniques for preparingpharmaceutical compositions including, but not limited to, by means ofconventional mixing, dissolving, granulating, dragee-making, levigating,emulsifying, encapsulating, entrapping or lyophilizing processes, andthe like.

Ingestible formulations of the present compositions may further includeany material approved by the United States Department of Agriculture forinclusion in foodstuffs and substances that are generally recognized assafe (GRAS), such as food additives, flavorings, colorings, vitamins,minerals, and phytonutrients. The term phytonutrients, as used herein,refers to organic compounds isolated from plants that have a biologicaleffect, and includes, but is not limited to, compounds of the followingclasses: isoflavonoids, oligomeric proanthcyanidins, indol-3-carbinol,sulforaphone, fibrous ligands, plant phytosterols, ferulic acid,anthocyanocides, triterpenes, omega 3/6 fatty acids, polyacetylene,quinones, terpenes, cathechins, gallates, and quercitin.

Dragee cores are provided with suitable coatings such as concentratedsugar solutions, which may also contain gum arabic, talc,polyvinylpyrrolidone, carbopol gel, polyethylene glycol, and/or titaniumdioxide, lacquer solutions, and suitable organic solvents or solventmixtures. Dyestuffs or pigments may be added to the tablets or drageecoatings for product identification or to characterize the quantity ofactive compound, (i.e., dosage).

Pharmaceutical preparations contemplated for oral administration includepush-fit capsules made of gelatin, as well as soft sealed capsules ofgelatin and a coating such as glycerol or sorbitol. In some embodiments,push-fit capsules can contain the active ingredients mixed with fillersor binders such as lactose or starches, lubricants such as talc ormagnesium stearate, and, optionally, stabilizers. In some soft capsuleembodiments, the active compounds are dissolved or suspended in asuitable liquid or solvent, such as fatty oils, liquid paraffin, orliquid polyethylene glycol, with or without stabilizers.

Pharmaceutical formulations for parenteral administration includeaqueous solutions of the active compounds. Aqueous injection suspensionsoptionally contain substances that increase the viscosity of thesuspension such as sodium carboxymethyl cellulose, sorbitol, or dextran.Additionally, suspensions of the active compounds may be prepared asappropriate oily injection suspensions. In this aspect, suitablelipophilic solvents or vehicles include fatty oils such as sesame oil,or synthetic fatty acid esters, such as ethyl oleate or triglycerides,or liposomes. Optionally, suspensions contain suitable stabilizers oragents that increase the solubility of the compounds thus allowing forthe preparation of highly concentrated solutions.

Compositions comprising a compound of the invention formulated in apharmaceutical acceptable carrier may be prepared, placed in anappropriate container, and labeled for treatment of an indicatedcondition. For gossypol compounds, conditions indicated on the label mayinclude treatment of conditions related to faulty regulation ofapoptosis, hyperproliferative diseases, cancers, acquired immunedeficiency syndrome (AIDS), degenerative conditions, and vasculardiseases. The pharmaceutical compositions may be provided as salts andcan be formed with many acids, including but not limited tohydrochloric, sulfuric, acetic, lactic, tartaric, malic, succinic, andthe like. Salts tend to be more soluble in aqueous or other protonicsolvents than are corresponding free base forms. In other cases, apreferred preparation comprises a lyophilized powder in 1 mM-50 mMhistidine, 0.1%-2% sucrose, or 2%-7% mannitol at a pH range of fromabout 4.5 to 5.5, optionally combined with buffer prior to use.

In preferred embodiments, dosing and administration regimes are tailoredby the clinician, or others skilled in the pharmacological arts, basedupon well known pharmacological and therapeutic considerationsincluding, but not limited to, the desired level of therapeutic effect,and the practical level of therapeutic effect obtainable. Generally, itis advisable to follow well-known pharmacological principles foradministrating chemotherapeutic agents (e.g., it is generally advisableto not change dosages by more than 50% at time and no more than every3-4 agent half-lives). For compositions that have relatively little orno dose-related toxicity considerations, and where maximum efficacy(e.g. destruction of cancer cells) is desired, doses in excess of theaverage required dose are not uncommon. This approach to dosing iscommonly referred to as the “maximal dose” strategy.

Additional dosing considerations relate to calculating proper targetlevels for the agent being administered, the agent's accumulation andpotential toxicity, stimulation of resistance, lack of efficacy, anddescribing the range of the agent's therapeutic index.

In certain embodiments, the present invention contemplates using routinemethods of titrating the agent's administration. One common strategy forthe administration is to set a reasonable target level for the agent inthe subject. In some preferred embodiments, agent levels are measured inthe subject's plasma. Proper dose levels and frequencies are thendesigned to achieve the desired steady-state target level for the agent.Actual, or average, levels of the agent in the subject are monitored(e.g., hourly, daily, weekly, etc.) such that the dosing levels orfrequencies can be adjusted to maintain target levels. Of course, thepharmacokinetics and pharmacodynamics (e.g., bioavailability, clearanceor bioaccumulation, biodistribution, drug interactions, etc.) of theparticular agent or agents being administered can potentially impactwhat are considered reasonable target levels and thus impact dosinglevels or frequencies.

Target-level dosing methods typically rely upon establishing areasonable therapeutic objective defined in terms of a desirable range(or therapeutic range) for the agent in the subject. In general, thelower limit of the therapeutic range is roughly equal to theconcentration of the agent that provides about 50% of the maximumpossible therapeutic effect. The upper limit of the therapeutic range isusually established by the agent's toxicity and not by its efficacy. Thepresent invention contemplates that the upper limit of the therapeuticrange for a particular agent will be the concentration at which lessthan 5 or 10% of subjects exhibit toxic side effects. In someembodiments, the upper limit of the therapeutic range is about twotimes, or less, than the lower limit. Those skilled in the art willunderstand that these dosing consideration are highly variable and tosome extent individualistic (e.g. based on genetic predispositions,immunological considerations, tolerances, resistances, and the like).Thus, in some embodiments, effective target dosing levels for an agentin a particular subject may be 1, . . . 5, . . . 10, . . . 15, . . . 20,. . . , . . . 75, . . . 100, . . . 200, . . . X %, greater than optimalin another subject. Conversely, some subjects may suffer significantside effects and toxicity related health issues at dosing levels orfrequencies far less (1, . . . 5, . . . 10, . . . 15, . . . 20, . . .50, . . . 75, . . . 100, . . . 200, . . . X %) than those typicallyproducing optimal therapeutic levels in some or a majority of subjects.In the absence of more specific information, target administrationlevels are often set in the middle of the therapeutic range.

In certain embodiments, genetic screening methods (e.g., SNP testing)are used to test a subject's predisposition to adverse reactions inresponse to particular chemotherapeutic agents or classes ofchemotherapeutic agents.

In still further embodiments, the present invention provides methods forrepetitive dosing and/or the continuous (semi-continuous) infusion oftherapeutic agents (e.g. small molecule Bcl-2 antagonists or agonists)sufficient to maintain, within a given therapeutic range, a steady-stateconcentration of agent(s) in a subject (e.g., in the subject's plasma).Those skilled in the art will appreciate that the compositions of thepresent invention can be administered such that a maintenance dose isprovided. Thus, in some embodiments, the chosen agent targetconcentration or rate of drug delivery is adjusted to balance the rateof drug loss. Those skilled in the art of administering chemotherapeuticagents will appreciate the calculations and measurements used to ensurethe balance of drug input versus drug loss to provide the desired targetlevel of drug (or other therapeutic agent) in the subject. Particularlyuseful in performing these calculations are defined levels of agentclearance and availability in a particular subject.

In additional embodiments, the present invention provides intermittentdosing methods, since marked fluctuations in agent concentration betweendoses are generally undesirable. In situations where the absorption anddistribution of the agent are balanced and spontaneous, concentrationfluctuations are dictated by the agent's elimination half-life.

In embodiments where the administered compositions are relativelynontoxic, maximal dosing methods can be used, because evenconcentrations of the agent several times that necessary for ensuringtherapeutic efficacy are well tolerated. In these embodiments, thedosing intervals are lengthened such that the concentration of the agentin the subject's system remains within the range of therapeuticeffectiveness for relatively long periods of time before being clearedfrom the subject and additional administrations are required to bringthe agent's level back into the therapeutically effective range. Thus,in certain of these embodiments, dosing intervals are longer than theagent's elimination half-life.

In other embodiments, where the compositions have relatively narrowtherapeutic ranges, it may be important calculate the maximum andminimum concentrations that will occur at particular dosing interval(s).In preferred embodiments, the minimal steady-state concentration ofadministered agents are determined using equations, optionally correctedfor the bioavailability of the agents, which are well known to thoseskilled in the pharmacological arts.

In still other embodiments, where the agents follow multiexponentialkinetics and the agents are administered orally, the estimation of themaximal steady-state concentration involves manipulation of severalexponential constants concerning agent distribution and absorption.

The present invention also provides methods for administering loadingdoses of an agent, or agents, to a subject. As used herein, a “loadingdose” is one or a series of doses that when given at the onset of atreatment quickly provide the target concentration of the therapeuticagent. In some embodiments, loading doses are administered to a subjecthaving an immediate need for the target level of an agent in relation tothe time required to attain a steady-state target level of the agentprovided using a constant rate of administration. Various negativeconsiderations should be weighed against the exigency of the subject'scondition and her need for a loading dose prior to its administration.These considerations include, but are not limited to: 1) loading dosesare often administered in one large bolus which may abruptly subject thepatient to a toxic concentration of the agent; 2) agents with longhalf-lives will remain at levels above the target-level as compared toagents administered under lower constant rate schemes. Loading doses areoften large, rapid, and given parenterally, thus dangerous side effectscan potentially occur at the site of administration before the agent canobtain equilibrium in the subject's plasma.

In preferred embodiments, the clinician rationally designs anindividualized dosing regimen based on known pharmacological principlesand equations. In general, the clinician designs an individualizeddosing regimen based on knowledge of various pharmacological andpharmacokinetic properties of the agent, including, but not limited to,F (fractional bioavailability of the dose), Cp (concentration in theplasma), CL (clearance/clearance rate), Vss (volume of drug distributionat steady state) Css (concentration at steady state), and t1/2 (drughalf-life), as well as information about the agent's rate of absorptionand distribution. Those skilled in the art are referred to any number ofwell known pharmacological texts (e.g., Goodman and Gilman's,Pharmaceutical Basis of Therapeutics, 10th ed., Hardman et al., eds.,2001) for further explanation of these variables and for completeequations illustrating the calculation of individualized dosing regimes.Those skilled in the art also will be able to anticipate potentialfluctuations in these variables in individual subjects. For example, thestandard deviation in the values observed for F, CL, and Vss istypically about 20%, 50%, and 30%, respectively. The practical effect ofpotentially widely varying parameters in individual subjects is that 95%of the time the Css achieved in a subject is between 35 and 270% that ofthe target level. For drugs with low therapeutic indices, this is anundesirably wide range. Those skilled in the art will appreciate,however, that once the agent's Cp (concentration in the plasma) ismeasured, it is possible to estimate the values of F, CL, and Vssdirectly. This allows the clinician to effectively fine tune aparticular subject's dosing regimen.

In still other embodiments, the present invention contemplates thatcontinuing therapeutic drug monitoring techniques be used to furtheradjust an individual's dosing methods and regimens. For example, in oneembodiment, Css data is used is to further refine the estimates of CL/Fand to subsequently adjust the individual's maintenance dosing toachieve desired agent target levels using known pharmacologicalprinciples and equations. Therapeutic drug monitoring can be conductedat practically any time during the dosing schedule. In preferredembodiments, monitoring is carried out at multiple time points duringdosing and especially when administering intermittent doses. Forexample, drug monitoring can be conducted concomitantly, withinfractions of a second, seconds, minutes, hours, days, weeks, months,etc., of administration of the agent regardless of the dosingmethodology employed (e.g., intermittent dosing, loading doses,maintenance dosing, random dosing, or any other dosing method). However,those skilled in the art will appreciate that when sampling rapidlyfollows agent administration the changes in agent effects and dynamicsmay not be readily observable because changes in plasma concentration ofthe agent may be delayed (e.g., due to a slow rate of distribution orother pharmacodynamic factors). Accordingly, subject samples obtainedshortly after agent administration may have limited or decreased value.

The primary goal of collecting biological samples from the subjectduring the predicted steady-state target level of administration is tomodify the individual's dosing regimen based upon subsequentlycalculating revised estimates of the agent's CL/F ratio. However, thoseskilled in the art will appreciate that early postabsorptive drugconcentrations do not typically reflect agent clearance. Earlypostabsorptive drug concentrations are dictated principally by theagent's rate of absorption, the central, rather than the steady state,volume of agent distribution, and the rate of distribution. Each ofthese pharmacokinetic characteristics have limited value whencalculating therapeutic long-term maintenance dosing regimens.

Accordingly, in preferred embodiments, when the objective is therapeuticlong-term maintenance dosing, biological samples are obtained from thesubject, cells, or tissues of interest well after the previous dose hasbeen administered, and even more preferably shortly before the nextplanned dose is administered.

In still other embodiments, where the therapeutic agent is nearlycompletely cleared by the subject in the interval between doses, thenthe present invention contemplates collecting biological samples fromthe subject at various time points following the previousadministration, and most preferably shortly after the dose wasadministered.

In yet other embodiments, when low clearance of the agent isproblematic, and toxicity issues are likely to result from itsaccumulation, the present invention contemplates measuring agentconcentrations immediately before the administration of the subsequentdose. In these embodiments, the determination of maximal and minimalagent concentrations are preferred.

The methods of the present invention further contemplate that when aconstant maintenance dosage is administered, steady state is reachedonly after expiration of four agent half-lives. Samples collected toosoon after dosing begins do not accurately reflect agent clearance.However, for potentially highly toxic agents, significant toxicity anddamage may already have ensued before expiration of the agent's fourthhalf-life. Thus, in some instances when it is important to maintaincontrol over agent concentrations, a first sample is taken after twohalf-lives, assuming a loading dose has not been administered. If agentconcentration already exceeds 90% of the eventual expected meansteady-state concentration, the dosage rate is halved, and anothersample obtained following an additional two half-lives. The dosage ishalved again if this sample once more exceeds the target level. If thefirst concentration does not exceed tolerable limits, subsequentadministrations are given at the initial dose rate. If the concentrationis lower than expected, the steady state can likely be achieved in abouttwo half-lives, and at this point the dosage rate can be adjusted asdescribed herein.

In embodiments comprising intermittent dosages, an additional concernrelated to timing of collection of concentration information, is if thesample was obtained immediately before the next scheduled dose,concentration will be at a minimal value, not the mean; however, asdiscussed herein, the estimated mean concentration can be calculatedusing equations known in the pharmacological arts.

When administering therapeutic agents having first-order kinetics, theaverage, minimum, and maximum concentrations at steady state arelinearly related to the dose and dosing rate. Thus, in theseembodiments, the ratio between the measured and the desired agentconcentrations is used to adjust dosing.

In another aspect of the present invention, computer programs arehelpful in designing dosing regimens. Typically, these programs takeinto account the measured drug concentrations and various factors (e.g.,measured or predicted) related to the individual subjects.

The present invention is not limited to any particular temporalconstraints on collecting subject, tissue, cell culture, or animal drugadministration data or samples. Moreover, the present invention is notlimited to collecting any particular type of samples (e.g., biologicalsamples) from a subject, tissue, cell culture, or test animal laboratoryanimal or otherwise. Indeed, in some embodiments, the present inventioncontemplates acquiring biological samples including, but not limited to,polynucleotides, polypeptides, lipids, carbohydrates, glycolipids, ionicspecies, metabolites, inorganic molecules, macromolecules andmacromolecular precursors as well as cell fractions, blood (e.g.,cellular and soluble or insoluble blood components including, but notlimited to, plasma, serum, metabolites, factors, enzymes, hormones, andorganic or inorganic molecules), exudates, secretions, sputum, excreta,cell and tissue biopsies, CNS fluids (cerebrospinal fluid), secretionsof lachrymal, salivary, and other glands, seminal fluids, etc., andcombinations of these or any other subcellular, cellular, tissular,organismal, systemic, or organismic biological materials. Biologicalsamples taken from a subject can be analyzed for chemical or biochemicalchanges (e.g., changes in gene expression) or other effects resultantfrom administration of the therapeutic agent. Further biological sampleand sampling consideration are described below.

In some of these embodiments, the biological and pharmacological effectsof the therapeutic compositions are determined using routine laboratoryprocedures on the collected samples including, but not limited to,microscopy (e.g., light, fluorescence (confocal fluorescence,immunofluorescence), phase-contrast, differential interference-contrast,dark field, or electron (transmission, scanning, cryo-), NMR,autoradiography), cell sorting techniques (e.g.,fluorescence-activated), chromatography techniques (e.g.,gel-filtration, ion exchange, hydrophobic, affinity, HPLC),electrophoretic techniques (e.g., SDS-PAGE, 2D-, 3D-, isoelectricfocusing), ultracentrifugation, immunocytochemical andimmunohistochemical technologies (e.g., ELISA, Western blotting, Immunoblotting), nucleic acid, including recombinant, technologies (e.g., PCR(inverse, reverse, nested), Northern blotting, Southern blotting,Southwestern blotting, in situ hybridization, FISH, nick-translation,DNAse footprinting, DNAse hypersensitivity site mapping, Maxam-Gilbertsequencing, Sanger sequencing, gel-shift (mobility shift) analysis, S1nuclease analysis, RNAse protection assay, CAT assays, transgenictechniques, knock-out techniques, and reporter gene systems), amino acidanalysis (e.g., Edman degradation), morphological, pathological, orphenotypical observations, and other observations with or without aid ofinstrumentation.

In some embodiments, subjects are questioned directly or indirectlyregarding their state of health and any changes attributable to theadministration of the therapeutic compositions (e.g., drugs, smallmolecules, and other therapeutic agents and techniques) and methods ofthe present invention.

Various interpatient and intrapatient pharmacokinetic considerationsaffect the design of dosing and administration regimens for individualpatients. For any given drug, there may be wide variations in itspharmacokinetic properties in a particular subject, and up to one-halfor more of the total variation in eventual response. The importance ofthese variable factors depends in part upon the agent and its usualroute of elimination. For example, agents that are primarily removed bythe kidneys and excreted unchanged into the urinary system, tend to showless interpatient variability in subjects with similar renal functionthan agents that are metabolically inactivated. Agents that areextensively metabolized, and agents that have high metabolic clearanceand large first-pass elimination rates show large differences ininterpatient bioavailability. Agents with slower rates ofbiotransformation typically have the largest variation in eliminationrates among individual subjects. Differences in subject genotypes alsoplays an important part in determining different metabolic rates.Pathological and physiological variations in individual subjects' organfunctions (e.g., renal or hepatic diseases) are major factors that canaffect an agent's rate of disposition. Kidney or liver diseases oftenimpair drug disposition and thus increase interpatient drug variability.Other factors (e.g. age) can also affect the responsiveness of targetedcells and tissues (e.g., the brain) to a particular composition ormethod of the present invention, and can alter the expected range of thetherapeutic target level for the agent.

When invasive patient samples (e.g., blood, serum, plasma, tissues,etc.) are necessary to determine the concentration of the therapeuticagent(s) in a subject, design of the collection procedures should beundertaken after considering various criteria including, but not limitedto: 1) whether a relationship exists between the concentration of theagent and any desired therapeutic effects or avoidable toxic effects; 2)whether these is substantial interpatient variability, but smallintrapatient variation in agent disposition; 3) whether it is otherwisedifficult or impractical to monitor the effects of the agent; and 4)whether the therapeutic concentration of the agent is close to the toxicconcentration. In still other embodiments, concentration measurementsare supplemented with additional measurements of pharmacokinetic,pharmacodynamic, or pharmacological effects.

In some instances, considerable interpatient response variations existafter the concentration of agent has been adjusted to the target level.For some agents, this pharmacodynamic variability accounts for much ofthe total variation in subject response. In some embodiments, therelationship among the concentration of an agent and the magnitude ofthe observed response may be complex, even when responses are measuredin simplified systems in vitro, although typically a sigmoidalconcentration-effect curve is seen. Often there is no singlecharacteristic relationship between agent concentration (e.g. in thesubject's plasma) and measured effect. In some embodiments, theconcentration-effect curve may be concave upward. In other embodiments,the curve is concave downward. In still other embodiments, the dataplots are linear, sigmoid, or in an inverted U-shape. Moreover, theresulting concentration-effect relationship curves can be distorted ifthe response being measured is a composite of several effects. In somepreferred embodiments, the composite concentration-effect curves areresolved into simpler component curves using calculations and techniquesavailable to those skilled in the art.

The simplified concentration-effect relationships, regardless of theirexact shape, can be viewed as having four characteristic variables:potency, slope, maximal efficacy, and individual variation. Thoseskilled in the art will appreciate that the potency of an agent ismeasured by the intersection of the concentration-effect curve with theconcentration axis. Although potency is often expressed as the dose ofan agent required to produce the desired effect, it is moreappropriately expressed as relating to the concentration of the agent inthe subject (e.g. in plasma) that most closely approximates the desiredsituation in an in vitro system to avoid complicating pharmacokineticvariables. Although potency affects agent dosing, knowledge of anagent's potency alone is relatively unimportant in clinical use so longas a dose sufficient to obtain the target level can be convenientlyadministered to the subject. It is generally accepted that more potentagents are not necessarily therapeutically superior to less potentagents. One exception to this principle, however, is in the field oftransdermal agents.

The maximum effect that an agent can induce in a subject is called itsmaximal or clinical efficacy. An agent's maximal efficacy is typicallydetermined by the properties of the agent and its receptor-effectorsystem and is reflected in the plateau of the concentration-effectcurve. In clinical use, however, an agent's dosage may be limited byundesirable effects (e.g., toxicity), and the true maximal efficacy ofthe agent may not be practically achievable without harming the subject.

The slope and shape of the concentration-effect curve reflects theagent's mechanism of action, including the shape of the curve that, atleast in part, describes binding to the agent's receptor. The rise ofthe concentration-effect curve indicates the clinically useful dosagerange of the agent. Those skilled in the art will appreciate that thedosage ranges recited herein are approximations based on soundpharmacological principles and that actual responses will vary amongdifferent individuals given the same concentration of an agent, and willeven vary in particular individuals over time. It is well known thatconcentration-effect curves are either based on an average response, orare tailored to reflect an actual response in a particular individual ata particular time.

The concentration of an agent that produces a specified effect in aparticular subject is called the individual effective concentration.Individual effective concentrations usually show a lognormaldistribution, resulting in a normal variation curve from plotting thelogarithms of the concentration against the frequency of achieving thedesired effect. A cumulative frequency distribution of individualsachieving the desired effect as a function of agent concentration iscalled the concentration-percent curve or quantal concentration-effectcurve. The shape of this curve is typically sigmoidal. The slope of theconcentration-percent curve is an expression of the pharmacodynamicvariability in the population rather than an expression of theconcentration range from a threshold to a maximal effect in theindividual patient.

Those skilled in the art will appreciate that the median effective dose(ED₅₀) is the dose of an agent sufficient to produce the desired effectin 50% of the population.

In preclinical drug studies, the dose (MTD) is determined inexperimental animals. The ratio of the MTD to the ED₅₀ is an indicationof the agent's therapeutic index and is a measurement of the selectivityof the agent in producing its desired effects. In clinical studies, thedose, or preferably the concentration, of an agent sufficient to producetoxic effects is compared to the concentration required for thetherapeutic effects in the population to provide a clinical therapeuticindex. However, due to individual pharmacodynamic variations in thepopulation, the concentration or dose of an agent required to producethe therapeutic effect in most subjects occasionally overlaps theconcentration that produces toxicity in some subjects despite the agenthaving a large therapeutic index. Those skilled in the art willappreciate that few therapeutic agents produce a single effect, thus,depending on the effect being measured, the therapeutic index for theagent may vary.

Preferred embodiments of the present invention provide approaches toindividualize dosing levels and regimens. In preferred embodiments,optimal treatment regimens for particular subjects are designed afterconsidering a variety of biological and pharmacological factorsincluding, but not limited to, potential sources of variation in subjectresponse to the administered agent(s), diagnosis specifics (e.g.,severity and stage of disease, presence of concurrent diseases, etc.),other prescription and non prescription medications being taken,predefined efficacy goals, acceptable toxicity limits, cost-benefitanalyses of treatment versus non treatment or treatment with othervarious available agents, likelihood of subject compliance, possiblemedication errors, rate and extent of agent absorption, the subject'sbody size and compositions, the agent's distribution, the agent'spharmacokinetic profile (e.g., physiological variables, pathologicalvariables, genetic factors and predispositions, drug interactions,potential drug resistances, predicted rate of clearance), potentialdrug-receptor interactions, functional state, and placebo effects.

In preferred embodiments, the clinician selects an appropriate markerfor measuring the ultimate effectiveness of the administered agent(s) inthe subject. The present invention contemplates that in someembodiments, appropriate markers of an agent's effectiveness include adecrease (or increase) in some measurable biological state, condition,or chemical level (e.g., toxin load, viral titer, antigen load,temperature, inflammation, blood cell counts, antibodies, tumormorphology, and the like). A large number of diagnostic procedures andtests are available for gathering information on various markersincluding, but not limited to, cell culture assays (e.g., invasionassays in soft-agar and the like), radiographic examination (e.g., chestX-ray), computed tomography, computerized tomography, or computerizedaxial tomography (CAT) scans, positron emission tomography (PET) scans,magnetic resonance imaging (MRI or NMRI), mammography, ultrasonography(transvaginal, transcolorectal), scintimammography (e.g., technetium 99msestamibi, technetium-99m tetrofosmin), aspiration (e.g., endometrial),palpation, PAP tests (e.g., smears), sigmoidoscopy (e.g., flexiblefiberoptic), fecal occult blood testing (e.g., Guaiac-based FOBT),digital rectal examination, colonoscopy, virtual colonoscopy (also knownas colonography), barium enema, stool analysis (See e.g., K. W. Kinzlerand B. Vogelstein, Cell, 87(2):159-70 (1996); S. M. Dong et al., J.Natl. Cancer Inst., 93(11):858-865 (2001); G. Traverso et al., N. Engl.J. Med., 346(5):311-20 (2002), G. Traverso et al., Lancet, 359(9304):403(2002); and D. A. Ahlquist et al., Gastroenterology, 119(5):1219-1227,(2000)), serum prostate-specific antigen (PSA) screening, endoscopy,gallium scans, marrow and tissue biopsies (e.g., core-needle,percutaneous needle biopsy, thoracotomy, endometrial, etc.) andhistological examinations, direct and/or indirect clinical observations(e.g., patient surveys, inquiries, or questionnaires), cytologicalsampling and collection of biological tissues, fluids, and markerstherein, (e.g., blood, urine (e.g., hematuria screening, urinarycytologic examinations), sputum (e.g., sputum cytology), feces, CNSfluids (e.g., LPs, spinal taps), blood products, including proteins andpeptides (e.g. Bcl-2 family proteins), cancer markers (e.g., CA 125(ovarian cancer), CA 15-3 (breast cancer), CEA (ovarian, lung, breast,pancreas, and gastrointestinal tract cancers), PSA (prostate cancer),p53 gene product, MIC2 gene product), metabolites (e.g.,vanillylmandelic acid (VMA), and homovanillic acid (HVA)), antigens(e.g., serum alpha-fetoprotein (AFP)), salts, minerals, vitamins,soluble factors, insoluble factors, nucleic acids, and the like).

For any compound used in the methods of the invention, thetherapeutically effective dose can be estimated initially from theconcentration of compounds that causes fifty percent cell growthinhibition and/or cell killing in the cell culture assays. Subsequently,dosages can be formulated in animal models (e.g., murine models) toachieve a desirable circulating concentration (target-level) range thatinduces the desired effect (e.g., apoptosis) in target cellscharacterized by elevated expression levels of Bcl-2 family proteins. Atherapeutically effective dose is the amount of gossypol compound (andin some embodiments, and additional therapeutic agents (e.g.,chemotherapeutic and/or anit-neoplastic agents) sufficient to ameliorate(or prevent) the symptoms of a disease or pathology (e.g., unregulatedcell proliferation, growth, invasion, autoimmunity).

In preferred embodiments, the toxicity and therapeutic efficacy ofagents is determined using standard pharmaceutical procedures in cellcultures or experimental animals, e.g., for determining the MTD and theED₅₀. Agents that exhibit large therapeutic indices are preferred. Thedata obtained from cell culture assays or animal models can be used toformulate dosing ranges in, for example, mammals (e.g., humans, Equuscaballus, Felis catus, and Canis familiaris, etc.). Preferable dosingconcentrations are near the calculated or observed ED₅₀ value for anagent. More preferable dosing concentrations are near an agent's ED₅₀value and cause little or no toxicity. Any given dosage may vary within,exceed, or be less than, the therapeutic index for any particular agent,depending upon the formulation, sensitivity of the patient, and theroute of administration.

In some embodiments, from 1, 2, 3, 4, 5, . . . 10, . . . 20, . . . 35, .. . 55, . . . 100, . . . 1,000, . . . 10,000, or more, units of time(e.g. minutes, hours, days, weeks, etc.) pass between the firstadministration of a therapeutic agent and subsequent administration. Insome of these embodiments, the interval(s) between any two or moreadministration points are constant (e.g., of equal duration). In stillother embodiments, the interval(s) between any two or moreadministration points are varied (e.g.; not of equal duration). Variedintervals can be either random or repeating and formulaic. Those skilledin the art will appreciate the steps necessary for designing andadjusting the dosing schedules and/or the dosing order of any one ormore agents.

Accordingly, preferred methods of the present invention are not limitedto providing any particular order or sequence for administering thegossypol compounds and non-gossypol additional therapeutic agents to asubject or to in vitro/ex vivo cells, tissues, or organs. For example,in some embodiments, a gossypol compound is administered to a subject orto in vitro cells, tissues, or organs, followed by one or moreadditional agents.

The present invention provides the following exemplary formulas toillustrate the flexibility available to the skilled clinician whendesigning dosing regimens comprising one or more gossypol compound andoptionally one or more non-gossypol compound (e.g., conventionalanticancer drug), therapy (e.g., radiotherapy), or technique (e.g.,surgical intervention). Thus, each variable represents the subjection ofthe patient or in vitro cells, tissues, or organs of interest to atherapeutic event (e.g., the administration of a gossypol compound). Itis understood that the exemplary formulas represent a portion of thetotal possible formulaic combinations and permutations of the particularvariables used in this exemplary. It is further understood, one skilledin the art could complete the exemplary listing of formulas to reciteevery possible permutation of the recited variables. It is alsounderstood that any implied time intervals between adjacent variablescan represent simultaneous therapeutic events, or the elapse ofmilliseconds, seconds, minutes, hours, days, weeks, months, or years.G1=a first administration of a gossypol compound; G2=a secondadministration of a gossypol compound, G3=a third administration of agossypol compound; Gn=a fourth administration of a gossypol compound;NGC1=a first administration of a non-gossypol compound, therapy, ortechnique; NGC2=a second administration of a non-gossypol compound,therapy, or technique; NGC3=a third administration of a non-gossypolcompound, therapy, or technique; and NGCn=a fourth administration of anon-gossypol compound, therapy, or technique, such that the followingexemplary administration regimens are possible: (G1); (G1, G2); (G1, G2,G3); (G1, G2, G3, Gn); (G1, NGC1, G1, NGC1, NGC2); (G1, NGC1, NGC2,NGC3); (G1, NGC1, NGC2, NGC3, NGCn); (G1, G2, NGC1); (G1, G2, NGC1,NGC2); (G1, G2, NGC1, NGC2, NGC3); (G1, G2, NGC1, NGC2, NGC3, NGCn);(G1, G2, G3, NGC1); (G1, G2, G3, NGC1, NGC2); (G1, G2, G3, NGC1, NGC2,NGC3); (G1, G2, G3, NGC1, NGC2, NGC3, NGCn); (G1, G2, G3, Gn, NGC1);(G1, G2, G3, Gn, NGC1, NGC2); (G1, G2, G3, Gn, NGC1, NGC2, NGC3); (G1,G2, G3, Gn, NGC1, NGC2, NGC3, NGCn); (NGC1, G1); (NGC1, G1, G2); (NGC1,G1, G2, G3); (NGC1, G1, G2, G3, Gn); (NGC1, NGC2, G1); (NGC1, NGC2, G1,G2); (NGC1, NGC2, G1, G2, G3); (NGC1, NGC2, G1, G2, G3, Gn); (NGC1,NGC2, NGC3, G1); (NGC1, NGC2, NGC3, G1, G2); (NGC1, NGC2, NGC3, G1, G2,G3); (NGC1, NGC2, NGC3, G1, G2, G3, Gn); (NGC1, NGC2, NGC3, NGCn, G1);(NGC1, NGC2, NGC3, NGCn, G1, G2); (NGC1, NGC2, NGC3, NGCn, G1, G2, G3);(NGC1, NGC2, NGC3, NGCn, G1, G2, G3, Gn); (G1, NGC1, G2); (G1, NGC1, G2,G3); (G1, NGC1, G2, G3, Gn); (G1, G2, NGC1, G3); (G1, G2, NGC1, G3, Gn);(G1, G2, G3, NGC1, Gn); (NGC1, G1, NGC2); (NGC1, G1, NGC2, NGC3); (NGC1,G1, NGC2, NGC3, NGCn); (NGC1, NGC2, G1, NGC3); (NGC1, NGC2, NGC3, G1,NGCn); (G1, NGC1, NGC2, G2); (G1, NGC1, NGC2, G2, G3); (G1, NGC1, NGC2,G2, G3, Gn); (G1, NGC1, NGC2, NGC3, G2); (G1, NGC1, NGC2, NGC3, G2, G3);(G1, NGC1, NGC2, NGC3, G2, G3, Gn); (G1, NGC1, NGC2, NGC3, NGCn, G2);(G1, NGC1, NGC2, NGC3, NGCn, G2, G3); (G1, NGC1, NGC2, NGC3, NGCn, G2,G3, Gn); (G1, NGC1, G2, NGC2); and (G1, NGC1, G2, NGC2, G3); (G1, NGC1,G2, NGC2, G3, Gn).

In some embodiments, from 1, 2, 3, 4, 5, . . . 10, . . . 20, . . . 35, .. . 55, . . . 100, . . . 1,000, . . . 10,000, or more, administrationsof an agent (or agents) are required to produce the desired effect(e.g., amelioration of a disease such as a neoplastic disease) in asubject or in in vitro cells, tissues, or organs of interest. Themethods of the present invention are not limited to the administrationof any particular gossypol compound, and optionally any one or moreadditional therapeutic agents, surgical interventions, orradiotherapies. In some embodiments, at least one gossypol compound isadministered to a subject substantially simultaneously with at least oneadditional therapeutic agent, surgical intervention, or radiotherapy.

The present invention is not limited to any particular pharmaceuticalformulations. Indeed, in some contemplated pharmaceutical compositionsand methods, a gossypol compound is formulated (e.g., in suspension)with a non-gossypol therapeutic agent. In other pharmaceuticalcompositions and methods, a multitude of gossypol compounds (e.g., 2 ormore) and optionally a multitude of non-gossypol therapeutic agents(e.g., 2 or more) are formulated in any combination thereof.Accordingly, the present invention is not limited to any particularformulations for combining two or more gossypol compounds and/or two ormore non-gossypol therapeutic agents. However, as described herein, andas routinely known in the chemical, biological, and pharmacologicalarts, certain gossypol compounds and non-gossypol therapeutic agents arepreferentially combined or segregated. Certain pharmaceuticalcompositions optionally comprise stabilizers, preservatives, adjuvants,pH modifiers, bioavailability modifiers, additives, excipients,diluents, lubricants, anti-oxidants, disintegrating agents, binders,thickening agents, emulsifiers, surfactants, sweeteners, pigments,flavorings, perfuming agents and the like, to improve variousbiological, chemical, or pharmaceutical characteristics.

Normal dosage amounts may vary from about 0.001 to 1,000 mg, up to atotal dose of about 1 g, depending upon the route of administration.Guidance as to particular dosages and methods of delivery are providedin the literature (See e.g., U.S. Pat. Nos. 4,657,760; 5,206,344; and5,225,212, U.S. Pat. No. 6,041,788, U.S. Pat. No. 6,273,727, U.S. Pat.No. 6,558,957, U.S. 20030017459A1, U.S. Pat. No. 5,782,799, U.S. Pat.No. 6,056,734, U.S. Pat. No. 6,528,086, U.S.20020065483A1, WO 0168169A1,and WO02072178A1 all of which are herein incorporated by reference).Administration of some agents to a patient's bone marrow may necessitatedelivery in a manner different from intravenous injections.

In some embodiments, the gossypol compounds are administered at a dosagerange of about 1 to 1,000 mg/day, preferably about 1 to 200 mg/day, morepreferably from about 10 to 80 mg/day, and most preferably from about 30to 40 mg/day. In some preferred embodiments, the gossypol compounds areadministered (e.g., orally) in a tolerable daily dose (e.g., 30 to 40mg/day) shown to have some biologic activity (e.g., alterations in Bclproteins, angiogenesis proteins, cell cycle alteration, apoptosismarkers, or alterations in Rb and Cyclin D1 levels). In a furtherembodiment, the gossypol compounds are administered at a dosage range ofabout 40 to about 500 mg/week).

In other embodiments, the effective dose of the gossypol compounds willtypically be in the range of about 0.01 to about 50 mg/kg, preferablyabout 0.1 to about 10 mg/kg of mammalian body weight, administered insingle or multiple doses. Generally, the compositions may beadministered to subjects in need of such treatment in a daily dose rangeof about 1 to about 2,000 mg per subject.

Preferred embodiments of the present invention provide pharmaceuticalcompositions and methods for administering an effective amount of agossypol compound (and optionally one or more non-gossypol therapeuticagents, such as conventional anticancer drugs) to a subject to inhibitcell (e.g., cancer cell) proliferation. In some other preferredembodiments, the present invention further provides pharmaceuticalcompositions and methods of coadministering an effective amount of atleast one conventional anticancer agent in addition to gossypol to apatient, such that cell (e.g., cancer cell) proliferation is inhibited.

In preferred embodiments, the subject has a disease characterized by theoverexpression of a Bcl-2 family protein (e.g., Bcl-2, Bcl-X_(L), Mcl-1,A1/BFL-1, and BOO-DIVA, etc.). In some embodiments, diseasescharacterized by overexpression of a Bcl-2 family protein include, butare not limited to, hyperproliferative diseases, cancers, acquiredimmune deficiency syndrome (AIDS), degenerative conditions, and vasculardiseases.

In still further embodiments, neoplastic diseases (e.g. cancers)suitable for treatment (and optionally prevention) by the presentcompositions and methods include, but are not limited to, breast cancer,prostate cancer, lymphoma, skin cancer, pancreatic cancer, colon cancer,melanoma, malignant melanoma, ovarian cancer, brain cancer, primarybrain carcinoma, head-neck cancer, glioma, glioblastoma, liver cancer,bladder cancer, non-small cell lung cancer, head or neck carcinoma,breast carcinoma, ovarian carcinoma, lung carcinoma, small-cell lungcarcinoma, Wilms' tumor, cervical carcinoma, testicular carcinoma,bladder carcinoma, pancreatic carcinoma, stomach carcinoma, coloncarcinoma, prostatic carcinoma, genitourinary carcinoma, thyroidcarcinoma, esophageal carcinoma, myeloma, multiple myeloma, adrenalcarcinoma, renal cell carcinoma, endometrial carcinoma, adrenal cortexcarcinoma, malignant pancreatic insulinoma, malignant carcinoidcarcinoma, choriocarcinoma, mycosis fungoides, malignant hypercalcemia,cervical hyperplasia, leukemia, acute lymphocytic leukemia, chroniclymphocytic leukemia, chronic granulocytic leukemia, acute granulocyticleukemia, acute myelogenous leukemia, chronic myelogenous leukemia,hairy cell leukemia, neuroblastoma, rhabdomyosarcoma, Kaposi's sarcoma,polycythemia vera, essential thrombocytosis, Hodgkin's disease,non-Hodgkin's lymphoma, soft-tissue sarcoma, osteogenic sarcoma, primarymacroglobulinemia, and retinoblastoma. However, the present invention isnot intended to be limited to treating (and optionally preventing) anyparticular type of cancer.

In some embodiments, diseases suspected of being characterized by havingelevated levels of Bcl-2 family protein(s) suitable for treatment (andoptionally prevention) by the present invention are selected byobtaining a sample of interest (e.g., cells, tissues, fluids, etc.)suspected of having high levels of Bcl-2 family proteins (e.g., Bcl-2,Bcl-X_(L), Mcl-1, A1/BFL-1, and BOO-DIVA, etc.), measuring the levels ofBcl-2 family proteins in the sample using one or more well establishedimmunohistochemical techniques (e.g., ELISA and Western blots, etc.),and comparing the levels of Bcl-2 family proteins in the sample withlevels of Bcl-2 family proteins in relevant reference nonpathologicalsamples. In other embodiments, diseases suspected of being characterizedby having elevated levels of one or more Bcl-2 family proteins (e.g.,Bcl-2, Bcl-X_(L), Mcl-1, A1/BFL-1, and BOO-DIVA, etc.) are selected bycomparing levels of one or more markers (e.g., polynucleotides,polypeptides, lipids, etc.) in a sample (e.g., cells, tissues, fluids,etc.) that directly or indirectly indicate elevated levels of Bcl-2family proteins in the sample as compared to levels of these markers inrelevant nonpathological samples. In still further embodiments, diseasessuspected of being characterized by having elevated levels of Bcl-2family proteins (e.g., Bcl-2, Bcl-X_(L), Mcl-1, A1/BFL-1, and BOO-DIVA,etc.) are selected from diseases that do not respond or that stopresponding to treatment with one or more conventional anticancertherapies (e.g., chemotherapy, radiation therapy, and/or surgicalintervention).

The present invention is not intended to be limited to theadministration routes chosen for delivering agents to a subject. Indeed,a number of suitable administration routes are contemplated, theselection of which is within the skill of those in the art.

In still other preferred embodiments taxanes (e.g., docetaxel) areadministered to a patient in combination with gossypol compounds. Theclassic docetaxel dosing schedule is 60-100 mg/m² every 3 weeks.However, recent studies suggest that taxanes can be given safely, withperhaps higher dose intensity, on a weekly schedule. (See e.g., J. D.Hainsworth et al., J. Clin. Oncology, 16:2164-2168 (1998); J. D.Hainsworth et al., J. Clin. Oncology, 19:3500-3505 (2001); and C.Kouroussis et al., Cancer Chemo. Pharm., 46:488-492 (2000)). The patienttoxicities associated with administering taxanes include neutropenia,asthenia, alopecia, hypersensitivity reactions, skin toxicity, andedema. Preferred embodiments of the present invention provide weeklyadministrations of taxanes to reduce patient toxicities while preservingagent efficacy. In other embodiments, administration of taxanes (e.g.docetaxel) more frequently than once a week during a patient's course oftreatment with the disclosed gossypol compounds is expected to producesynergistic effects.

While the present invention is not limited to any particular mechanism,nor to any understanding of the action of the agents being administered,the following example provides a description of an exemplary testingprocedure used to determine potential drug interactions between gossypolcompounds and one or more anticancer agents that are candidates forco-administration with gossypol.

Docetaxel is extensively metabolized by CYP3A4, a specific cytochromep450 enzyme. Pharmacokinetic data obtained for docetaxel indicates widevariance in its clearance between patients. Poor docetaxel clearance mayresult in an increase in the area-under-the-curve (AUC) and thus greaterpatient toxicity. Several investigations have reported that gossypoldecreases cytochrome P-450 and mixed-function oxidases, although theseresults have been challenged, and no human studies have been performedwhich specifically address this issue. Thus, it is possible thatgossypol could inhibit CYP3A4 activity and lead to toxic docetaxelaccumulation in some patients.

In one embodiment, the patient is administered a daily dose of agossypol compound for 1 week prior to receiving their first dose ofdocetaxel. The pharmacokinetic profile of docetaxel in the patient'ssystem is evaluated after the patient receives their first dose ofdocetaxel. (See, R. Bruno et al., J. Clin. Oncol., 16:187-196 (1998)).Docetaxel dosing is started at a reduced dose of about 15 mg/m²/week.The dose of docetaxel is gradually escalated to a maximally tolerateddose of about 35 mg/m²/week. Simultaneously, information will becollected on effects of gossypol administration on the phenotypicexpression of CYP3A4. The phenotypic expression of CYP3A4 is measuredeasily and reproducibly using an erythromycin breath test (ERMBT). (See,e.g., P. Watkins, Pharmacogenetics, 4:171-184 (1994); and J. Hirth etal., Clin. Cancer Res., 6:1255-1258 (2000)). The ERMBT test has beenshown to predict steady state trough blood levels of drugs that areCYP3A4 substrates. Consequently, some embodiments of the presentinvention are directed to the co-administration of gossypol compoundsand taxanes (e.g., docetaxel) using an ERMBT to determine potential druginteractions. Those skilled in the art will appreciate that similartesting methodologies can be utilized to determine potentialinteractions between gossypol compounds and additional candidatecompounds for co-administration.

In some embodiments, standard immunohistochemical techniques are used toanalyze patient samples before, during, or after treatment with themethods and compositions of the present invention. In some of theseembodiments, the immunohistochemical techniques are used to quantifychanges in the levels of Bcl-2 family proteins (e.g. Bcl-2, Bcl-X_(L),and Bax, etc.). For example, in some embodiments, antibodies to Bcl-2(DAKO, Carpinteria, Calif.), Bcl-X_(L), and/or Bax (Zymed, South SanFrancisco, Calif.) are used to determine levels of these Bcl-2 proteinsin a patient sample. In preferred embodiments, results from theimmunohistochemical studies are interpreted using well-establishedcriteria known to those in the art, wherein any cytoplasmic or nuclearstaining are considered positive. The expression levels of Bcl-2,Bcl-X_(L), and Bax can be determined by counting at least 1,000neoplastic cells in each case and expressed as a percentage. Expressionwill be considered high when the percentage of positive cells is >25%for Bcl-2, and Bcl-X_(L), and >50% for Bax. (See e.g., G. Rassidakis etal., Amer. J. Path., 159:527-535 (2001); and S. Shi et al., J.Histochem. Cytochem., 39:741-748 (1991)). In other embodiments,intermittent sampling of whole blood is conducted. Samples aresubsequently prepared for fluorescence activated cell sorting (FACS)analysis of Bcl-2 and Bcl-X_(L) expression in peripheral bloodlymphocytes (PBLs) and for immunomagnetic selection of circulatingepithelial cells.

In some embodiments, the primary endpoint of dosing studies occurs whenthe maximum tolerated dose of a gossypol compound (at a particular dailydose, e.g., 30 mg/day), optionally co-administered with a anticancerdrug, is established. In some embodiments, dose-limiting toxicity (DLT)is established when a given sample (e.g., a cell, tissue, or fluidsample) exhibits >500 neutrophils per given unit, or upon observing anyGrade 3 or 4 toxicities while the patient is being studied.

In still some other embodiments, to evaluate dose escalation a minimumof 9 weeks of treatment is required for 2 or more patients at each doselevel. The maximum tolerated dose (MTD) is defined as the dose at which33% of patients experience DLT. In preferred embodiments, doses areallocated to patients according to the criteria described in theContinual Reassessment Method (J. O'Quigley et al., Biometrics 46:33-48(1990)) called Time-to-Event CRM or (TITE-CRM). Briefly, the TITE-CRMmethod provides a model for the time to occurrence of toxic response asa function of dose, and allows information from all patients enrolled ina trial to be used when allocating new patient dose levels. Because thismethod is very flexible in terms of the number of patients treated ateach dose, subjects may be continuously recruited throughout a trial,without recruitment pauses, as long as patients are treated at a doseconsistent with the safety profile.

In preferred embodiments, diseased cells and tissues are subjected toassays for cell viability and signs of induction of apoptosis (e.g.,morphological changes, DNA integrity, mitochondria pathways, alterationsof expression of Bcl-2 family proteins, and caspase activation as wellas upstream and downstream effectors of caspases and caspaseinhibitors). Those skilled in the art will be able to readily design andexecute assays to test these and other cellular and biochemicalparameters in treated cells and tissues.

X. Exemplary Combination Therapies

The present invention provides the following exemplary embodimentscomprising the therapeutic administration of a gossypol compound incombination with additional therapeutic agents such as conventionalchemotherapy agents (anticancer drugs) and radiation therapy.

A. Exemplary Combination Therapies

Experiments were conducted to further evaluate the in vivo therapeuticefficacy of various gossypol compounds, such as (−)-gossypol, alone andin combination with one or more conventional antineoplastic therapeuticagents. Experiments were conducted in various mouse xenograft tumormodels, including breast cancer cell line MDA-231, prostate cancer cellline PC-3, ovarian cancer cell line A2780 and its Bcl-X_(L) transfectedclones, colon cancer cell line HT-29, and non-small cell lung cancerA549 xenograft mouse models. In several models, the administration of(−)-gossypol alone provided good antitumor activity and inhibition oftumor growth. In other models, administration of (−)-gossypol withdocetaxel, paclitaxel, or cisplatin achieved superior antitumor activityand cancer cell inhibition as compared to the administration of gossypolalone. Some animals receiving a combination of gossypol and aconventional antineoplastic therapeutic agent showed complete tumorregression.

In certain generalized experiments, 4-6 weeks old male athymic NCr-nu/nunude mice were used in coadministration studies involving administrationof a gossypol compound, e.g. (−)-gossypol, in combination with aconventional anticancer chemotherapeutic agent. In one embodiment, tumorxenografts were established by injecting MDA-MD-231 cells (1×10⁶) intoboth side fat pads, or by injecting PC-3, HT-29, or A549 cells (5×10⁶)into both flanks of each mouse. Tumors were measured with a caliper intwo dimensions, length (a), and width (b). The tumor volumes werecalculated by (length×width², a×b²). Treatments were initiated at day5-10 post inoculation, when the majority of tumor diameters were about5-7 mm and tumor volume had reached about 50 mm³. For efficacy testing,racemic gossypol and/or isolated (−)-gossypol enantiomer were givenorally at 7.5 to 30 mg/kg every day in 0.1 ml of 10% ethanol for fourweeks.

In certain other combination treatment experiments, racemic gossypoland/or isolated (−)-gossypol enantiomer were given orally to xenograftedmice at daily doses of from 7.5 to 15 mg/kg. 24 hours later afteradministration of the gossypol compound test animals were given a doseof conventional anticancer chemotherapeutic agent. Conventionalanticancer chemotherapeutic agents were administered as follows:docetaxel at 7.5 mg/kg given intravenously once a week; and/orpaclitaxel at 10 mg/kg, three times per week intraperitoneally. Thecombination treatments lasted for 3 consecutive weeks. All mice in thecontrol group were injected with 0.1 ml PBS. Approximate tumor sizes andbody weights were measured two to three times a week. Average tumorvolumes and standard deviations were calculated for each group andplotted.

Antitumor activity curves for racemic gossypol and the (−)-gossypolenantiomer were plotted with observation time on the X-axis, andcorresponding tumor volume (geometric mean) on the Y-axis. The areaunder the curve (AUC) was calculated by Tai's mathematical model foreach curve, and shown as geometric means and 95% confidential intervals.The difference of AUC among treatment groups was compared by ANOVA.T-test was used for other analysis.

Previous studies have shown that overexpression of Bcl-X_(L) protectscancer cells from docetaxel induced apoptosis. Thus, the presentinvention contemplates that compositions and methods for coadministeringgossypol compounds, e.g., (−)-gossypol with conventional anticancerchemotherapeutics, such as docetaxel, provides a more effectivetreatment than either agent used alone, especially in diseasecharacterized by high expression levels of Bcl-2 family proteins (e.g.,Bcl-2 and/or Bcl-X_(L)). While the present invention is not limited toany particular mechanisms, it is contemplated that administration ofgossypol compounds to diseased cells and tissues overexpressing Bcl-2family proteins (e.g., Bcl-2 and/or Bcl-X_(L)) sensitizes these diseasedcells and tissues to the therapeutic effects of conventionalchemotherapeutic agents, such as docetaxel and/or radiation therapy.Accordingly, various other experiments were performed to test theeffectiveness of coadministering (−)-gossypol with docetaxel as atherapeutic treatment for neoplastic diseases, such as cancer.Representative data from these experiments in a mouse xenograft model ofhuman breast cancer MDA-231 are provided in FIG. 18. Briefly, in FIG. 18docetaxel treatment was started at day 7 and was given intravenously ata weekly dose of 7.5 mg/kg for 3 weeks. The results show that treatmentwith docetaxel alone in a sub-optimal dose (7.5 mg/kg weekly) wassufficient to inhibit tumor growth. However, the coadministration of(−)-gossypol, at any one of three doses levels (e.g., 7.5, 15 or 30mg/kg), with docetaxel achieved greater anticancer activity andinhibition of tumor cell growth. Three out of ten mice treated with thegossypol docetaxel combination had complete tumor regression. Overall,there was more than 90% inhibition of tumor growth in the combinationgroup as compared to the control group. Statistical analyses wereperformed using a mixed-effects repeated measures model that accuratelytakes into account the correlation within an animal over time, andbetween tumors within an animal. The data were modeled using the naturallogarithm of tumor volume, which is standard practice for tumor growthmodels. A comparison of tumor growth in animals receiving (−)-gossypolalone and docetaxel alone was performed. An exemplary comparison of(−)-gossypol at 7.5 mg/kg and docetaxel is provided in Table 7.

TABLE 7 (−)-Gossypol Docetaxel 7.5 mg/kg 7.5 mg/kg Combination(−)-Gossypol — <0.0001 <0.0001 7.5 mg/kg Docetaxel <0.001 — <0.0001 7.5mg/kg Combination <0.0001 0.0028 —

In a subset of the mice treated with either docetaxel alone orcombination therapy, a second round of treatments with the same regimenwas initiated at day 45. The average tumor volume before the secondcycle treatments was about 2,000 mm³. Tumors in the docetaxel alonetreated group continued to grow, thus all the mice were sacrificed dueto the tumor burden. In contrast, in the combination treatment groups,animals displayed tumor regression and a 50% reduction of tumor volume(FIG. 19). The data shows that (−)-gossypol is very effective atpotentiating the agent docetaxel when administered in combinationtreatments even at levels where (−)-gossypol administered alone is not,or only partially, effective.

The outcome of coadministration of (−)-gossypol and conventionalanticancer chemotherapy agents was further tested in additional mousexenograft cancer models. The results of one experiment conducted in themouse A549 non-small cell lung carcinoma xenograft are shown in FIG. 20.The A549 cell line expresses high levels of Bcl-X_(L) protein. The micewere administered a daily oral dose of 7.5 mg/kg (−)-gossypol incombination with a weekly dose of paclitaxel (i.p., 15 mg/kg). Over 90%tumor inhibition was observed. The results of the combination treatmentwere statistically significant compared to administration of either drugalone (P<0.002 vs. paclitaxel alone; P<0.001 vs. (−)-gossypol alone). Noadverse effects were seen with any dose.

Summaries of still other in vivo studies of (−)-gossypol in variouscancer xenograft models are provided in Tables 8-15, as shown below.

TABLE 8 Drug/Dose/ Tumor Host Route Regimen Results MDA-231 Balb/c nude(−)-Gossypol at (−)-gossypol q day There was no difference between thehuman mouse, all 7.5, 15 or 30 mg/kg, for 4 weeks untreated control andthe vehicle breast female, 4-6 p.o. beginning ~7 days control. cancer,weeks old Docetaxel at after tumor cell There was dose-dependentbilateral 8 mice (16 7.5 mg/kg, i.v. inoculation inhibition of tumorgrowth by (−)- fat-pad tumors) per Controls: Docetaxel q week gossypol(G-) alone. At a dose of xenografts group Untreated, and for 3 weeks 30mg/kg of G-, there was 40% (~50 mm³ vehicle beginning ~1 day tumorgrowth inhibition, but lower at start of control. after gossypol dosesof G- (15 or 7.5 mg/kg) alone treatment) treatment did not achievesignificant anti- or 8 days after tumor effect in this experiment. tumorcell Docetaxel on this dose regimen. inoculation achieved about 70%tumor growth Drugs given alone inhibition alone, but tumors grew or incombination back 2-3 weeks after treatment stopped. Combinations of G-at any of the three doses with docetaxel at 7.5 mg/kg all achievedsignificant tumor growth inhibition. At 7.5 mg/kg of G- in combinationwith docetaxel, there was more than 90% tumor growth inhibition with p <0.01. There was tumor regression in 3 mice treated with combinationregimen. There was no weight loss or death in mice treated withgossypol.

TABLE 9 Drug/Dose/ Tumor Host Route Regimen Results PC-3 NCr-nu Bothracemic Both racemic Racemic gossypol at 15 mg/kg, human nude mouse,gossypol and gossypol and (−)- daily p.o. for 26 days, achieved prostateall male, 5-6 (−)-gossypol at gossypol q day for limited tumor growthinhibition cancer, weeks old 15 mg/kg, p.o. 4 weeks beginning (15.6% onday 42). The (−)-gossypol bilateral 5 mice (10 Docetaxel at ~7 daysafter tumor (G-) alone achieved moderate tumor xenografts tumors) per7.5 mg/kg, i.v., cell inoculation growth inhibition (52% on day 42, inflank group in combination Docetaxel q week p = 0.08). region with (−)-for 3 weeks Docetaxel at this dose regimen (~100 mm³ gossypol onlybeginning ~11 days achieved about 67% tumor growth at start of Andvehicle after gossypol inhibition alone (p = 0.005), whereas treatment)control treatment the combinations of G- with or 16 days after docetaxelat 7.5 mg/kg achieved tumor cell 84% tumor growth inhibition asinoculation compared with vehicle control Drugs given alone (p = 0.002).The combination or in combination treatment is also more significantthan the docetaxel alone (P = 0.059). More importantly, there wascomplete tumor regression in 3 out of 5 mice treated with combinationregimen. There was no weight loss in mice treated with gossypol.

TABLE 10 Drug/Dose/ Tumor Host Route Regimen Results PC-3 NCr-nu RacemicBoth racemic Racemic gossypol at 15 mg/kg, human nude mouse, gossypol at15 mg/kg, gossypol and (−)- daily p.o. for 28 days, achieved prostateall male, 5-6 p.o. gossypol q day for limited tumor growth inhibitioncancer, weeks old (−)-Gossypol at 4 weeks beginning (39% on day 56, p =0.145) compared bilateral 8 mice (16 7.5 and 15 mg/kg, ~17 days after tovehicle controls. The (−)-gossypol xenografts tumors) per p.o. tumorcell (G-) alone achieved moderate in flank group Docetaxel atinoculation antitumor activity (60% on day 56, region 7.5 mg/kg, i.v.Docetaxel q week p = 0.0028). The difference between (~120 mm³ Andvehicle for 3 weeks the racemic and (−)-gossypol is at start of controlbeginning ~5 days significant (p = 0.0055). treatment) after gossypolDocetaxel at this dose regimen treatment achieved about 70% tumor growthor 23 days after inhibition alone compared to tumor cell controls (p =0.0016), whereas the inoculation combinations of G- with docetaxel Drugsgiven alone at 7.5 mg/kg achieved 89.9% tumor or in combinationinhibition as compared with vehicle control (p = 0.004). The combinationtreatment is more effective as compared with the (−)-gossypol alone ordocetaxel alone (p = 0.009). More importantly, there was complete tumorregression in 5 out of 8 mice in the combination treatment regimen,whereas there was no tumor regression with docetaxel alone. There was noweight loss in mice treated with gossypol.

TABLE 11 Drug/Dose/ Tumor Host Route Regimen Results PC-3 NCr-nu(−)-Gossypol at (−)-Gossypol q day Either (−)-gossypol (G-) or cisplatinhuman nude mouse, 7.5 mg/kg, p.o. for 4 weeks (CDDP) alone at this doseregimen prostate all male, 5-6 Cisplatin at 5 mg/kg, beginning ~11 daysachieved only 20-25% tumor growth cancer, weeks old i.v. after tumorcell inhibition. (p = 0.85 for G-, p = 0.79 bilateral 8 mice (16Controls: inoculation for CDDP, not significant), whereas xenograftstumors) per Untreated, and Cisplatin twice q the combinations of G- within flank group vehicle week for 2 weeks cisplatin at 5 mg/kg achieved65% region control. beginning ~6 days tumor growth inhibition as (~74mm³ after gossypol compared with vehicle control at start of treatment(p = 0.0038) or either drug alone treatment) or 17 days after (p = 0.028for G-, p = 0.013 for tumor cell CDDP). inoculation There was nocomplete tumor Drugs given alone regression in the either drug alone oror in combination the combination treatment regimen. There was 10-15%weight loss for CDDP alone, and 20-23% weight loss for the combinationregimen during the treatment. Mice started to gain back the weight 1-2weeks after the CDDP treatment stopped.

TABLE 12 Drug/Dose/ Tumor Host Route Regimen Results HT-29 NCr-nu(−)-Gossypol at (−)-Gossypol q day The (−)-gossypol (G-) alone humannude mouse, 7.5 mg/kg, p.o. for 4 weeks achieved moderate tumor growthcolon all male, 10 Cisplatin at 10 mg/kg, beginning ~6 days inhibition(47% on day 29). The cancer, weeks old i.v. after tumor cell differencebetween the (−)-gossypol bilateral 5 mice (10 And untreated inoculationand control is significant (p = 0.02). xenografts tumors) per controlCisplatin twice q There was no cisplatin or in flank group week for 2weeks combination group data as the dose region beginning ~1 day ofcisplatin used was too high. Most (~160 mm³ after gossypol mice weredead in the cisplatin at start of treatment treated group during the2^(nd) week of treatment) or 7 days after the treatment. tumor cellinoculation Drugs given alone or in combination

TABLE 13 Drug/Dose/ Tumor Host Route Regimen Results A549 NCr-nu(−)-Gossypol at (−)-Gossypol q day The (−)-gossypol (G-) alone humannon- nude mouse, 7.5 mg/kg, p.o. for 4 weeks achieved moderate tumorgrowth small cell all female, Paclitaxel at beginning ~16 daysinhibition (57% on day 31). The lung 5-6 weeks 15 mg/kg, i.p. aftertumor cell difference between the (−)-gossypol carcinoma old Anduntreated inoculation and control group is significant bilateral 5 mice(10 control Paclitaxel twice q (p = 0.0459). xenografts tumors) per weekfor 3 weeks Paclitaxel at this dose regimen in flank group beginning ~3days achieved about 67% tumor growth region after gossypol inhibitionalone (p = 0.0166) whereas (~75 mm³ treatment the combinations of G-with at start of or 19 days after paclitaxel at 7.5 mg/kg achievedtreatment) tumor cell 76% tumor growth inhibition as inoculationcompared with vehicle control Drugs given alone (p = 0.0024). Thecombination or in combination treatment is more effective as comparedwith the (−)-gossypol alone (p = 0.0034) or paclitaxel alone (p =0.0038). There were no complete tumor regressions seen in thisexperiment. There was no weight loss in mice treated with gossypoland/or Paclitaxel.

TABLE 14 Drug/Dose/ Tumor Host Route Regimen Results PC-3 NCr-nu(−)-Gossypol at (−)-Gossypol 5 The (−)-gossypol (G-) or radiation humannude mouse, 10 mg/kg, p.o. times q week for 4 alone achieved limitedtumor prostate all male, 5-6 Radiation at 2 weeks beginning growthinhibition in this dose cancer, weeks old Gy per day, ~13 days afterregimen (about 20%, P = 0.3 or 0.7, bilateral 5 mice (10 total 30 Gy,tumor cell day 39, not significant). xenografts tumors) per locallyinoculation Combinations of G- with radiation in flank group towardstumor Radiation 2 Gy 5 achieved 93% tumor growth region site, this istimes q week for 3 inhibition as compared with vehicle (~150 mm³radiation plus weeks beginning control (p = 0.0024, day 39). The atstart of vehicle. ~5 days after combination treatment is more treatment)Controls: gossypol treatment effective as compared with the (−)-Untreated, and or 18 days after gossypol alone (p = 0.0013, day 39)vehicle alone tumor cell or radiation alone (p = 0.0011, day control.inoculation 39). G- and radiation There were no complete tumor givenalone or in regressions seen in this experiment. combination There wasno significant weight loss in mice treated with gossypol and/orradiation.

TABLE 15 Drug/Dose/ Tumor Host Route Regimen Results PC-3 NCr-nu(−)-Gossypol at (−)-Gossypol 5 The (−)-gossypol alone achieved humannude mouse, 10 mg/kg, p.o. times q week for 4 limited tumor growthinhibition in prostate all male, 5-6 Radiation at 2 weeks beginning thisdose regimen (about 30%, cancer, weeks old Gy per day, ~13 days after p= 0.549, not significant). bilateral 8 mice (10 total 30 Gy, tumor cellThe radiation alone achieved xenografts tumors) per locally inoculationmoderate tumor growth inhibition in in flank group towards tumorRadiation 2 Gy 5 this dose regimen as compared with region site, this istimes q week for 3 the control group (55%, p = 0.0459, (~70 mm³radiation plus weeks beginning day 37). at start of vehicle. ~5 daysafter Combinations of G- with radiation treatment And vehicle gossypoltreatment achieved 91.5% tumor growth alone control. or 18 days afterinhibition as compared with vehicle tumor cell control (p = 0.0024, day37). The inoculation combination treatment is more G- and radiationeffective as compared with the (−)- given alone or in gossypol alone (p= 0.0112) or combination radiation alone (p = 0.0068). There wascomplete tumor regression in 10 out of 16 tumors in the combinationtreatment regimen, whereas there was no tumor regression with singleagent alone. There was no significant weight loss in mice treated withgossypol and/or radiation.

B. Gossypol Compounds in the Treatment of Head and Neck Squamous CellCarcinoma

There are about 40,000 new cases of head and neck squamous cellcarcinoma (HNSCC) diagnosed in the United States each year. The 5-yearsurvival rates for patients afflicted with HNSCC are typically not good,in part because the treatment of locally advanced head and neck cancerswith conventional chemo- and radiation therapies is hampered by theemergence of resistant cancer cells.

Abnormal programmed cell death plays a critical role in cancerprogression and outcome following conventional chemo- and radiationtherapies. While the present invention is not limited to any particularmechanisms, it is contemplated that HNSCCs develop resistance toconventional chemo- and radiation therapies by developing the ability tosuppress chemotherapy-induced apoptosis. (A. M. Petros et al., ProteinSci., 9:2528-2534 (2000); A. F. Schott et al., Oncogene, 11:1389-1394(1995); and J. C. Reed et a., Ann. Oncol., 5:61-65 (1994)). Studies haveshown that 74% of laryngeal tumors express high levels of Bcl-X_(L) and15% overexpress Bcl-2 (D. K. Trask et al., Laryngoscope, 112:638-644(2002)), and low expression of Bcl-X_(L) has been associated withexcellent response in advanced laryngeal cancers to chemo- and radiationtherapies. Bcl-2 and Bcl-X_(L) are homologous members of the Bcl-2family of proteins. Bcl-2 and Bcl-X_(L) function as potent suppressorsof mitochondrial-mediated apoptosis.

In in vitro studies, gossypol induced apoptosis in breast, colon, andprostate cancer cells that had high levels of Bcl-2 or Bcl-X_(L)expression. As the majority of HNSCCs express high levels of Bcl-X_(L),the present invention provides compositions and methods foradministering gossypol compounds, e.g., (−)-gossypol, to treat HNSCCsand other head and neck cancers.

Data obtained during the development of the present invention shows acorrelation between response to (−)-gossypol and Bcl-X_(L)/Bcl-X_(S)expression ratios among the HNSCC cell lines examined. Thus, it iscontemplated that anti/pro-apoptotic protein expression ratios representa predictive measure of cellular apoptotic potential. Additional datasuggests that when Bcl-X_(L) is the dominant anti-apoptotic factor, thatBcl-X_(S) is the dominant anti-apoptotic factor in HNSCCs. In Example17, in the panel of 10 HNSCC cell lines, only one, UM-SCC-74B, had nodetectable expression of Bcl-X_(L) but a medium level of Bcl-2 proteinexpression. All of the tumor HNSCC cell lines tested were much moresensitive to (−)-gossypol than were normal fibroblast cell lines. Whilenot being limited to any particular mechanisms, the present inventioncontemplates that sensitivity in HNSCC cell lines is related to theabsence of a deregulated cell survival pathway in normal cells.Bcl-X_(L) is expressed in fibroblasts in low levels and (−)-gossypoldoes not induce either apoptosis or growth inhibition until highconcentrations are reached.

Experiments conducted during the development of the present inventionfound that p53 status plays an important role in (−)-gossypol-inducedapoptosis in some cancers (e.g., HNSCCs). In this regard, cell lineswith wild type p53 exhibited much more robust induction of apoptosis inresponse to (−)-gossypol treatment relative to tumor cells with mutantp53. The present invention is not limited however to any particularmechanisms, and indeed a mechanistic understanding of the presentinvention is not required to make and use the present compositions andmethods. Thus, it is contemplated that cell-killing by (−)-gossypol, asdetermined in the MTT assays conducted in Example 17, is not solelythrough apoptosis.

In some embodiments, cisplatin resistance in HNSCCs correlates to thepresence of wild type p53 and high Bcl-X_(L) expression in in vitrostudies. Animal studies demonstrate that tumors with high expression ofp53, correlating to p53 mutation, are more likely to be controlled bychemo- and radiation therapy treatment protocols. In some embodiments,low expression levels of Bcl-X_(L) correlates to induction chemotherapyusing cisplatin and 5-fluorouracil. Thus, the present invention showsthat a subset of tumors and cell lines with wild type p53 and highexpression of Bcl-X_(L) are resistant to cisplatin-based therapeuticregimens. However, in some preferred embodiments, the compositions andmethods of the present invention show that gossypol compounds, e.g.,(−)-gossypol, provides significant antitumor activity against cell lineswith wild type p53 and high levels of Bcl-X_(L) that are unlikely torespond to conventional anticancer chemotherapeutic agents includingcisplatin (e.g. UM-SCC-1 and -6; both have high levels of Bcl-X_(L)expression and wild-type p53). Accordingly, in some embodiments, thepresent invention provides compositions and methods for the combinedadministration of conventional anticancer chemotherapeutic agents, suchas cisplatin, with gossypol compounds, (e.g., (−)-gossypol), thateffectively treat typically chemo- and/or radiation therapy resistantHNSCCs. In some additional embodiments, the present inventioncontemplates diagnostic methods for detecting expression of a Bcl-2family protein (e.g. Bcl-2 and/or Bcl-X_(L)) and p53 as an aid inselecting an appropriate therapeutic intervention (e.g., avoidance ofcisplatin, or use of cisplatin with the compositions and methods of thepresent invention).

(−)-Gossypol selectively inhibits UM-SCC cell growth. Ten UM-SCC celllines exposed to (−)-gossypol in a 6-day MTT assay (Example 17) showeddose-dependent inhibition of cell growth over a range from 0.5 to 10 μM,while fibroblast cell lines showed little change relative to untreatedcontrols at doses<10 μM (FIG. 21). FIG. 21 shows growth inhibition ofHNSCC cells by (−)-gossypol. UM-SCC and human fibroblast cell lines werecontinuously exposed to varying concentrations of (−)-gossypol in 6-dayMTT cell survival assays. Control wells contained media (DMEM) withvehicle alone. For each data point n=5. In this assay, (−)-gossypol hada mean IC₅₀ of 5.57±2.57 μM in HNSCC cell lines which is significantlylower than the mean IC₅₀ of 20.31±9.20 μM in fibroblasts (p=0.0142).(−)-Gossypol selectively inhibits head and neck squamous cell carcinoma.

Additional experiments described in Example 17 determined the proteinexpression levels of Bcl-2, -X_(L), and -X_(S) in UM-SCC cell linesusing Western blot analyses (See, FIG. 22). Bcl-X_(L) is expressed inthe majority of UM-SCC cell lines (9/10) in this panel, with only UM-SCC74B lacking detectable expression. Bcl-2 is expressed in UM-SCC-74B,-17B and -6. All cell lines expressed Bcl-XS at some level.

In still other embodiments, levels of Bcl-2 family protein expressionwere evaluated for correlation with (−)-gossypol's in vitro activity.The relative levels of expression for Bcl-X_(L) and Bcl-X_(S) wereevaluated by densitometry but no statistically significant correlationwith sensitivity to (−)-gossypol was identified (r=−0.14, p=0.70 andr=0.20, p=0.58). As both Bcl-X_(L) and -X_(S) expression are common andvary among cell lines, the possibility that the Bcl-X_(L)/Bcl-X_(S)ratio was associated with (−)-gossypol's in vitro effect wasinvestigated. Interestingly, as shown in FIG. 23, there appeared to be acorrelation between the Bcl-X_(L)/Bcl-X_(S) expression ratios and cellline sensitivity to (−)-gossypol (r=−0.83, p=0.0029) among the celllines examined. FIG. 23 shows Bcl-X_(L)/Bcl-X_(S) protein ratios and(−)-gossypol 6-day MTT IC₅₀ values. Densitometry measurements forBcl-X_(L) and Bcl-X_(S) were recorded for three independent Westernblots performed on cell lines. These ratios were calculated as theBcl-X_(L) measurement divided by the Bcl-X_(S) measurement from the sameexperiment. Ratios were then averaged and plotted in a linear fashion onthe Y1 axis; bars, +SD. IC₅₀ values for (−)-gossypol were plotted on theY2 axis. A clear inverse correlation is shown between Bcl-X_(L)/X_(S)ratio and sensitivity to (−)-gossypol (r=−0.83, p=0.0029).

In Example 17 four cell lines, UM-SCC-1, -6, -12 and -14A, were shown toexhibit significant cell death following 48 hour exposure to 10 μM(−)-gossypol, with surviving (trypan blue excluding) fractions of 20%,9%, 14% and 16% respectively relative to untreated controls (p=<0.0001).

TUNEL assays for apoptosis were performed on fibroblasts and a subset offour UM-SCC cell lines that spanned the spectrum of sensitivity to(−)-gossypol (FIGS. 24A-24C). Briefly, FIGS. 24A-24C show apoptosisafter (−)-gossypol as measured by a fluorescent flow cytometric TUNELassay. Open peaks represent BrdU labeling of untreated cells. Shadedpeaks indicate BrdU labeling of cell populations following 48-hourtreatment with 10 μM (−)-gossypol; FIG. 24A, UM-SCC-cell lines with wildtype p53; FIG. 24B, UM-SCC-cell lines with mutant p53; and FIG. 24Cnormal fibroblast cells. No clear correlation between proportion ofapoptotic cells and cell line sensitivity to (−)-gossypol was found.However, UM-SCC-1, which is very sensitive to (−)-gossypol, displayedthe highest apoptotic fraction following (−)-gossypol treatment(AI=90.1%). In contrast, fibroblast cell lines showed no induction ofapoptosis. Of the four tumor cell lines, UM-SCC-1 (IC₅₀=2 μM) andUM-SCC-6 (IC₅₀=8 μM) cell lines have wild type p53, while UM-SCC-12(IC₅₀=4 μM) and UM-SCC-14A (IC₅₀=11 μM) contain p53 mutations. The twowild-type p53 tumor cell lines displayed a mean apoptotic index (AI) of85.2%±6.9 (UM-SCC-1, AI=90.1%, UM-SCC-6, AI=80.3%). In contrast, the twocell lines with mutant p53 have a mean apoptotic index of 20.7%±9.3(UM-SCC-12, AI=27.2%, UM-SCC-14A, AI=14.1%). This difference isstatistically significant with a p-value of 0.0157.

C. Administration of (−)-Gossypol Compounds in Combination withRadiation Therapy

The present invention provides methods for administering gossypolcompounds with radiation therapy. The methods of the present inventioncomprising the administration of gossypol compounds (and optionallyother chemotherapeutic agents) in conjunction with radiation therapy arenot intended to be limited to any particular dosing or administrationroutes. For example, in some embodiments, the chemotherapeutic agents,including gossypol compounds and any other chemotherapeutic agent(s),are administered prior to the subject receiving at least one session orcourse of radiation therapy. In other embodiments, the subject receivesat least one session of radiation therapy prior to the administration ofchemotherapeutics (e.g., gossypol compounds and optionally otheranticancer agents). In yet other embodiments, the chemotherapeuticadministrations overlap, at least to some extent, with sessions ofradiation therapy. Those skilled in the fields of medicine (e.g.,oncology, radiology, dosimetry, medical physics, pathology, histology,and the like) and pharmacology will appreciate that, in general, thetreatment of diseases, and especially cancers, including the therapeuticadministration of compositions and methods of the present invention, isa dynamic process.

In preferred embodiments, when radiation therapy is used with thepharmaceutical compositions and methods of the present invention, thesubject's medical team considers a number of factors including, but notlimited to, the type, amount, delivery, field size, and duration of theradiation, the subject's health and medical history, the type and stageof cancer being treated, and many other factors.

The present invention is not limited by the types, amounts, or deliveryand administration systems used to deliver the therapeutic dose ofradiation to a subject. For example, the subject may receive photonradiotherapy, particle beam radiation therapy, other types ofradiotherapies, and combinations thereof. In some embodiments, theradiation is delivered to the subject using a linear accelerator. Instill other embodiments, the radiation is delivered using a gamma knife.

The source of radiation can be external or internal to the patient.External radiation therapy is most common and involves directing a beamof high-energy radiation to a tumor site through the skin using, forinstance, a linear accelerator. While the beam of radiation is localizedto the tumor site, it is nearly impossible to avoid exposure of normal,healthy tissue. However, external radiation is usually well tolerated bypatients. Internal radiation therapy involves implanting aradiation-emitting source, such as beads, wires, pellets, capsules,particles, and the like, inside the body at or near the tumor siteincluding the use of delivery systems that specifically target cancercells (e.g., using particles attached to cancer cell binding ligands).Such implants can be removed following treatment, or left in the bodyinactive. Types of internal radiation therapy include, but are notlimited to, brachytherapy, interstitial irradiation, intracavityirradiation, radioimmunotherapy, and the like.

The subject may optionally receive radiosensitizers (e.g.,metronidazole, misonidazole, intra-arterial Budr, intravenousiododeoxyuridine (IudR), nitroimidazole,5-substituted-4-nitroimidazoles, 2H-isoindolediones,[[(2-bromoethyl)-amino]methyl]-nitro-1H-imidazole-1-ethanol,nitroaniline derivatives, DNA-affinic hypoxia selective cytotoxins,halogenated DNA ligand, 1,2,4 benzotriazine oxides, 2-nitroimidazolederivatives, fluorine-containing nitroazole derivatives, benzamide,nicotinamide, acridine-intercalator, 5-thiotretrazole derivative,3-nitro-1,2,4-triazole, 4,5-dinitroimidazole derivative, hydroxylatedtexaphrins, cisplatin, mitomycin, tiripazamine, nitrosourea,mercaptopurine, methotrexate, fluorouracil, bleomycin, vincristine,carboplatin, epirubicin, doxorubicin, cyclophosphamide, vindesine,etoposide, paclitaxel, heat (hyperthermia), and the like),radioprotectors (e.g., cysteamine, aminoalkyl dihydrogenphosphorothioates, amifostine (WR 2721), IL-1, IL-6, and the like).Radiosensitizers enhance the killing of tumor cells. Radioprotectorsprotect healthy tissue from the harmful effects of radiation.

A typical course of treatment for most types of cancer involves the useof radiation therapy. Radiation therapy uses a beam of high-energyparticles or waves, such as X-rays and gamma rays, to eradicate cancercells by inducing mutations in cellular DNA. In that cancer cells dividemore rapidly than normal cells, tumor tissue is more susceptible toradiation than normal tissue. Radiation also has been shown to enhanceexogenous DNA expression in exposed cells. In a preferred embodiment,the inventive method further comprises administering a dose or multipledoses of radiation to a patient over the therapeutic period.

In one embodiment, intratumoral delivery of a nucleic acid sequenceencoding cytotoxic factors (e.g., TNF-α) and confocal radiation to thetumor site results in localized delivery of two potent anti-cancertreatment modalities. When the nucleic acid sequence encoding thecytotoxic factor is operably linked to a radiation-inducible promoter,radiation potentiates the factor's production and maintains therapeuticlevels of factor at the tumor site continuously throughout the period ofradiation therapy. The present invention contemplates that the disclosedmethods provide additive or synergistic effects of radiation andcytotoxic factor, and gossypol compounds to eradicate tumor cells.

Any type of radiation can be administered to a patient, so long as thedose of radiation is tolerated by the patient without unacceptablenegative side-effects. Suitable types of radiotherapy include, forexample, ionizing (electromagnetic) radiotherapy (e.g., X-rays or gammarays) or particle beam radiation therapy (e.g., high linear energyradiation). Ionizing radiation is defined as radiation comprisingparticles or photons that have sufficient energy to produce ionization,i.e., gain or loss of electrons (as described in, for example, U.S. Pat.No. 5,770,581 incorporated herein by reference in its entirety). Theeffects of radiation can be at least partially controlled by theclinician. The dose of radiation is preferably fractionated for maximaltarget cell exposure and reduced toxicity.

The total dose of radiation administered to a patient preferably isabout 0.01 Gray (Gy) to about 100 Gy. More preferably, about 10 Gy toabout 65 Gy (e.g., about 15 Gy, 20 Gy, 25 Gy, 30 Gy, 35 Gy, 40 Gy, 45Gy, 50 Gy, 55 Gy, or 60 Gy) are administered over the course oftreatment. While in some embodiments, a complete dose of radiation canbe administered over the course of one day, the total dose is ideallyfractionated and administered over several days. Desirably, radiotherapyis administered over the course of at least about 3 days, e.g., at least5, 7, 10, 14, 17, 21, 25, 28, 32, 35, 38, 42, 46, 52, or 56 days (about1-8 weeks). Accordingly, a daily dose of radiation will compriseapproximately 1-5 Gy (e.g. about 1 Gy, 1.5 Gy, 1.8 Gy, 2 Gy, 2.5 Gy, 2.8Gy, 3 Gy, 3.2 Gy, 3.5 Gy, 3.8 Gy, 4 Gy, 4.2 Gy, or 4.5 Gy), preferably1-2 Gy (e.g., 1.5-2 Gy). The daily dose of radiation should besufficient to induce destruction of the targeted cells. If stretchedover a period, radiation preferably is not administered every day,thereby allowing the subject to rest and the effects of the therapy tobe realized. For example, radiation desirably is administered on 5consecutive days, and not administered on 2 days, for each week oftreatment, thereby allowing 2 days of rest per week. However, radiationcan be administered 1 day/week, 2 days/week, 3 days/week, 4 days/week, 5days/week, 6 days/week, or all 7 days/week, depending on the subject'sresponsiveness and any potential side effects. Radiation therapy can beinitiated at any time in the therapeutic period. Preferably, radiationis initiated in week 1 or week 2, and is administered for the remainingduration of the therapeutic period. For example, radiation isadministered in weeks 1-6 or in weeks 2-6 of a therapeutic periodcomprising 6 weeks for treating, for instance, a solid tumor.Alternatively, radiation is administered in weeks 1-5 or weeks 2-5 of atherapeutic period comprising 5 weeks. These exemplary radiotherapyadministration schedules are not intended however to limit the presentinvention.

In modern oncology, radiation therapy is used to treat a wide variety ofcancers with varying degrees of effectiveness. X-ray irradiationstrongly induces apoptosis. For example, radiation therapy is currentlyused to treat all stages of localized prostate cancer, however, certainclinical and radiobiological evidence indicates that prostate cancercells are relatively resistant to radiation therapy. In particular,PC-3, a human prostate cancer cell line, is hormone-refractory andresistant to current chemo- and radiation therapies. The presentinvention determined that PC-3 cells express very high levels of bothBcl-2 and Bcl-X_(L) protein. Overexpression of Bcl-2 and Bcl-X_(L)proteins provides, at least in part, resistance to chemo- or radiationtherapy induced apoptosis that is observed in many types of cancer cells(e.g. PC-3 prostate cancer cell line). In some preferred embodiments,chemo- or radiation therapy resistant cancers (e.g., prostate cancer)expressing high levels of Bcl-2 family proteins (e.g., Bcl-2 and/orBcl-X_(L), and the like) are targets for treatment using the methods andcompositions of the present invention. While any understanding ofparticular mechanisms is not important to make and use the compositionsand methods of the present invention, and the present invention is notso limited, it is contemplated that antagonizing the anti-apoptoticfunctions of Bcl-2 and/or Bcl-X_(L) using the gossypol compounds (andoptionally administration of other therapeutic agents) of the presentinvention overcomes the resistance to conventional radiation therapiesseen in many types of cancers.

EXAMPLES

The following examples are provided to demonstrate and furtherillustrate certain preferred embodiments of the present invention. Theexamples are not to be construed as limiting the scope of the presentinvention.

Example 1 Homology Modeling

The sequence of human Bcl-2 was obtained from Gene Bank (entrygi4557355) (SEQ ID NO:1). (See, FIG. 1). The NMR structure of Bcl-X_(L)(pdb code: 1BXL from the protein databank), which has 45% amino acidsequence identity, 56% sequence similarity and 3% gaps with Bcl-2, wasused as the template. The structure of Bcl-2 was built using thehomology-modeling program MODELLER (version 4.0). (A. Sali et al.,Structure, Function, and Genetics, 23:318-326 (1995); and A. Sali, Curr.Opin. Biotech., 6:437-451 (1995)). Further refinement was done using themolecular dynamics program CHARMM (version 27b2). (B. R. Brooks, J.Comput. Chem., 4:187-217 (1983)). Hydrogen atoms were assigned to themodeled structure using the program QUANTA (Molecular Simulations Inc.,San Diego, Calif.). The Bak BH3 peptide was placed into the Bcl-2 BH3domain binding site in the same orientation as in the NMR structure ofBcl-X_(L) in complex with the Bak BH3 peptide (1BXL in proteindatabank). (S. Michael et al., Science, 275:983-986 (1997)). The complexstructure was solvated by inserting it into a 60 Å diameter TIP3P watersphere and deleting solvent molecules that have heavy atoms at less then2.5 Å from any protein heavy atom.

MD simulations were done using the all atom parameter set from the MSICHARMM force field (ref 23) in QUANTA 98, a constant dielectric, ∈=1 andconstant temperature, T=300 K. The leap frog method with 1 fs time stepwas applied for numerical integration. Long-range electrostatic forceswere treated with the force switch method with a switching range of 8-12Å. (See, B. R. Brooks et al., J. Comput. Chem., 4:187-217 (1983)). Vander Waals forces were calculated with the shift method and a cutoff of12 Å. The nonbond list was kept to 14 Å and updated heuristically.Solvent waters were kept from evaporating by using a sphericalmiscellaneous mean field potential as implemented in CHARMM. (B. R.Brooks, supra). The solvated protein was energy minimized using 100cycles using the Steepest Descent method and additional 1000 cyclesusing the Adopted-Basis Newton Raphson method. This was followed by 3.0ns MD simulations. The simulation was performed on an Origin2000computer at the Advanced Biomedical Computing Center at the NationalInstitutes of Health. The representation of the refined structure ofBcl-2 in complex with Bak BH3 peptide is shown in FIGS. 2A and 2B.

Example 2 Expression and Purification of the Bcl-X_(L) Protein

Recombinant Bcl-X_(L) protein with a N-terminal His-tag wasoverexpressed from the pET15b expression vector (Novagen, Darmstadt,Germany). In this construct, the putative C-terminal membrane-anchoringregion (residues 214-237) and a loop between helix 1 and helix 2(residues 49-88) were removed to facilitate protein purification. Thisloop was previously shown to be dispensable for the anti-apoptoticactivity of the protein. (See, S. W. Muchmore et al., Nature,381:335-341 (1996)). The current construct of Bcl-X_(L) produces about20 mg of the purified Bcl-X_(L) protein from IL of cell culture.

The protein samples for NMR studies were uniformly labeled with ¹⁵N forscreening and uniformly double labeled with ¹⁵N and ¹³C for structurecharacterization according to the methods described in M. Jansson etal., J. Biomol. NMR, 7:131-141 (1996), and M. L. Cai et al., J. Biomol.NMR, 11:97-102 (1998).

Example 3 Resolution of (−)-Gossypol and (+)-Gossypol from RacemicGossypol

Racemic gossypol acetic acid purchased from the National CancerInstitute (Bethesda, Md.) or commercial sources (e.g., Sigma-AldrichCorp., St. Louis, Mo.) was dissolved in diethyl ether, washed twice withwater to remove the acid and the ether layer was concentrated by rotaryevaporation. To a solution of 1.04 g of gossypol (2 mmol) in 50 ml ofCH₂Cl₂ was added 1 g of L-phenylalanine methyl ester hydrochloride (4.6mmol), 0.4 g of NaHCO₃ (4.7 mmol), 3 g of 4 Å molecular sieves, and 1 mlof 2-propanol, the resulting mixture was stirred at room temperatureovernight under N₂ in the dark and filtered. The L-phenylalanine methylester reacts with the aldehyde groups of gossypol to form a Schiff'sbase with two diastereoisomers which were then resolved on a normalsilica flash chromatography column. The filtrate was concentrated, andthe residue was purified by chromatography on silica gel eluting withhexanes:EtOAc=3:1 to give two fractions. Acid hydrolysis of the twofractions in 5 N H Cl:THF=1:5 (room temperature, overnight) regeneratedthe individual gossypol enantiomers, respectively. The first fractionwith a higher R_(f) value contained (−)-gossypol, and the secondfraction with a lower R_(f) value contained (+)-gossypol. The crudegossypol fractions were extracted into ether from the residue afterremoving THF from the reaction mixture. The gossypol fractions were thenpurified by chromatography on silica gel and eluted withhexanes:EtOAc=3:1 to give optically pure gossypol, with a yield of30-40% in two steps. The optical rotatory dispersion values for theseproducts were α_(D)=−352° (c=0.65, CHCl₃) for (−)-gossypol, andα_(D)=+341° (c=0.53, CHCl₃), in agreement with literature values. (J. Siand L. Huang, Kexue Tongbao, 28:1574 (1983)) (See, FIG. 25).

Example 4 Fluorescence Polarization Based Binding Assays andDetermination of the Binding of Various Gossypol Compounds to Bcl-2 andBcl-X_(L) Proteins

The present invention used established sensitive and quantitative invitro fluorescence polarization-based (FP) binding assays to determinethe in vitro binding affinity of small molecule inhibitors (e.g.,gossypol compounds) to both Bcl-2 and Bcl-X_(L). (See e.g., J. L. Wanget al., Cancer Res., 60:1498-1502 (2000); J. L. Wang et al., Proc. Natl.Acad. Sci. U.S.A., 97:7124-7129 (2000); A. Degterev et al., Nat. CellBiolog., 3:173-182 (2001); and I. J. Enyedy et al., J. Med. Chem.,44:4313-4324 (2001)). The FP-based assays were used to monitor thedisplacement of fluorescently labeled BH3 domain peptides fromrecombinant Bcl-2 or Bcl-X_(L) proteins. Once a fluorescently labeledBH3 peptide (e.g., Bad, Bak, Bid BH3 peptides, and the like) binds toBcl-2 or Bcl-X_(L) protein, fluorescence polarization is enhanced. Whena small molecule inhibitor, such as a gossypol compound, binds to Bcl-2or Bcl-X_(L) it displaces the fluorescently labeled BH3 domain peptide,thus decreasing the observed fluorescence polarization. Determination ofthe binding affinities of the Bcl-2 and Bcl-X_(L) proteins is importantto determining their selectivity. Although the structures of Bcl-2 andBcl-X_(L) are very similar, there are some differences between the twoproteins. Accordingly, small molecule inhibitors of Bcl-2 and/orBcl-X_(L) (e.g., gossypol compounds) may display selectivity between thetwo proteins. In additional embodiments, the binding of gossypolcompounds to Bcl-2 and Bcl-X_(L) is further determined and confirmedusing the NMR methods outlined herein.

Initial screening of Bcl-2 inhibitors (e.g., gossypol, enantiomers,derivatives, and pharmaceutically acceptable salts thereof) was carriedout at 200 μM. If significant inhibition was observed for an inhibitor(larger than 50%), its IC₅₀ value was determined. Five ml of the testcompounds, in reaction buffer, were added to wells containing a tracerand Bcl-2 or Bcl-X_(L) proteins provided at the same concentration asthe test compound. Final FP readings were taken after a 10-minincubation at room temperature. For making IC₅₀ determinations ofinitial test compounds, 9 to 10 test compound concentrations (i.e.,between 1 nM and 200 μM) were used. Non-labeled Bak peptide was used asa positive control. Inactive compounds were used as negative controls.

In one embodiment, Bcl-2 fluorescence polarization assays were carriedout as follows. Fluorescein-labeled 16-mer peptide tracer Flu-Bak-BH3(GQVGRQLAIIGDDINR (SEQ ID NO:9) derived from Bak BH3 domain) wassynthesized and labeled at the amino terminus. Forty-six-kDa solublerecombinant GST-fused Bcl-2 protein was purchased from Santa CruzBiotechnology (Santa Cruz, Calif.). Reaction were carried out in a totalvolume of 20 μl per well (containing 10 μl of 1× phosphate-bufferedsaline, 5 μl of the GST-Bcl-2 protein, and 5 μl of peptide tracer). Thereaction wells were incubated at room temperature for 20 min. FPreadings were taken at 485 nm and 535 nm using an ULTRA READER (TecanU.S. Inc, Research Triangle Park, N.C.). A series of validationexperiments were performed by analyzing the maximal and minimal signalsobtained from the background, buffer, Bcl-2 protein, tracer, and themixture of Bcl-2 protein and tracer. The Kd of binding between Bcl-2protein and the 16-mer fluorescein-labeled peptide was determined bytitrating Bcl-2 protein at concentrations ranging from 5.4 nM to 540 nMand fluorescent tracer concentrations ranging from 0.145 nM to 1,450 nM.Optimal binding was obtained at a final concentration of 290 nMfluorescent tracer and 270 nM Bcl-2 protein. To verify the observedspecificity, binding of the fluorescently labeled peptide and nonlabeled16-mer peptide were compared in a binding competition assay. The dataindicate that nonlabeled 16-mer peptide was able to abrogate binding ofthe labeled tracer, with an IC₅₀ of approximately 0.3 μM. The binding ofracemic gossypol to Bcl-2 protein under these assay conditions is shownin FIG. 3.

In another embodiment, Bcl-X_(L) fluorescence polarization assays werecarried out as follows. Fluorescein-labeled 16-mer peptide tracerFlu-Bak-BH3 (GQVGRQLAIIGDDINR (SEQ ID NO:9) derived from Bak BH3 domain)was synthesized and labeled at the amino terminus. Soluble recombinantHis-fused Bcl-X_(L) protein, as described in Example 2, was used. Thecompetitive binding curve for racemic gossypol is shown in FIG. 3. FIG.6A shows gossypolone's competitive inhibition of Bak BH3 peptide bindingto Bcl-X_(L) protein under the described assay conditions. FIG. 6B showsthat (−)-gossypol ethyl Schiff's base displays time-dependent inhibitionof the binding between Bak BH3 peptide and Bcl-X_(L) protein. Thepresent invention is not limited to any mechanism. Indeed, anunderstanding of any particular mechanism is unnecessary to practice(make and use) the present invention. Nonetheless, it is contemplatedthat the above finding results from the hydrolysis of the Schiff's baseto form free (−)-gossypol.

In another embodiment, Bcl-2 fluorescence polarization assays werecarried out as follows. A 25-residue Bad BH3 peptide(NLWAAQRYGRELRRMSDEFVDSFKK (SEQ. ID. NO.: 10)) labeled at the N-terminuswith 6-carboxyfluorescein succinimidyl ester (FAM) as a fluorescence tag(Flu-Bad-25) was synthesized. The Bcl-2 protein used in these assays wasa soluble recombinant GST-fusion (Santa Cruz Biotechnology). An aliquoteof the test compound and preincubated Bcl-2 protein (0.020 μM) andFlu-Bad-25 peptide (0.005 μM) in the assay buffer (100 mM potassiumphosphate, pH 7.5; 100 μg/ml bovine gamma globulin; 0.02% sodium azide(Invitrogen, Corp., Carlsbad, Calif.) were added to black Dynex 96-wellround-bottom plates (Fisher Scientific, Inc., Hampton, N.H.). In eachexperiment, a bound peptide control containing Bcl-2 and Flu-Bad-25peptide (equivalent to 0% inhibition), and free peptide controlcontaining only free Flu-Bad-25mer (equivalent to 100% inhibition), wereincluded on the assay plate. The polarization values were measured after4 hrs of incubation when the binding reached equilibrium using an ULTRAREADER (Tecan U.S. Inc., Research Triangle Park, N.C.). The K_(d) valueof the binding of Bad 25-mer BH3 peptide to Bcl-2 was determined to be6.9 nM (FIG. 26). IC₅₀ values, the inhibitor concentration at which 50%of bound peptide is displaced, were determined from a plot usingnonlinear least-squares analysis. Curve fitting was performed usingGRAPHPAD PRISM software (GraphPad Software, Inc., San Diego, Calif.).The non-labeled Bad peptide was used as the positive control. The K;values were calculated using the following equation:

K _(i) =[I] ₅₀/([L] ₅₀ /K _(d) +[PL] ₀ /[L] ₀+1)=[I] ₅₀ /[L] ₅₀ /K _(d)+[P] ₀ /K _(d)+1)  (Equation 1)

The competitive binding curves of racemic gossypol, (−)-gossypol and(+)-gossypol in directly blocking binding between Bad 25-residue BH3peptide and Bcl-2 are shown in FIG. 4.

In another embodiment, Bcl-X_(L) fluorescence polarization assays werecarried out as follows. Bid 21-residue BH3 peptide labeled with6-carboxyfluorescein succinimidyl ester (FAM) was synthesized.Recombinant Bcl-X_(L) proteins, as described in Example 2, were used.Various gossypol compounds (e.g., racemic gossypol, (−)-gossypol, and(+)-gossypol) were analyzed using the following assay conditions: 15 nMBcl-X_(L) and 2.5 nM Flu-Bid peptide in assay buffer containing 50 mMBis-Tris, pH 7.4 with 0.01% bovine gamma globulin. The K_(d) value ofBid 21-mer BH3 peptide biding to Bcl-X_(L) was determined to be 2.9 nM(FIG. 27). The competitive binding curves of racemic gossypol,(−)-gossypol, and (+)-gossypol in directly blocking the binding betweenBad 21-residue BH3 peptide and Bcl-X_(L) are shown in FIG. 5.

The competitive binding curve of racemic apogossypol in directlyblocking binding between Bad 25-residue BH3 peptide and Bcl-2 is shownin FIG. 45.

The competitive binding curve of racemic apogossypol in directlyblocking the binding between Bad 21-residue BH3 peptide and Bcl-X_(L) isshown in FIG. 46.

Example 5 Docking Gossypol into Bcl-2

This example describes docking studies of gossypol performed using theDOCK program (version 4.0.1) (S. Makino et al., J. Comput. Chem.,18:1812-1825 (1997)) and the LigandFit program available in the Cerius2molecular modeling package. (Molecular Simulations Inc., San Diego,Calif.). The structure of Bcl-2 used for refined docking is the same asthat used for database searching. The structure of gossypol used fordocking was built and minimized in the QUANTA program (MolecularSimulations Inc., San Diego, Calif.). Atomic charges of gossypolcompounds and the Bcl-2 protein were assigned using the Geisteigermethod as implemented in the Sybyl program (Tripos, Inc., St. Louis,Mo.). Refined docking was performed with the DOCK program (version4.0.1) using 500 configurations per ligand building cycle, 5,000 maximumorientations of the anchor, 1,000 maximum minimization cycles and 10,000maximum iterations per cycle. The default convergence criteria were usedfor energy refinement of the docked structure. The docking withLigandFit program (Receptor Science, Singapore) was done using a gridthat covered the whole BH3 binding site with 0.2 Å grid spacing.Parameters for gossypol and Bcl-2 were assigned using the 1997 releaseof the CFF force field. The position of the ligand was optimized usingthe maximum allowed 999,999 Monte Carlo steps. The default parameterswere used for convergence criteria during refinement with the LIGAND FITprogram (Accelrys, Inc., San Diego, Calif.).

Example 6 Confirmation of Gossypol Binding to Bcl-X_(L) by NMR

The binding of gossypol compounds (e.g., racemic gossypol, (−)-gossypol,and (+)-gossypol) to Bcl-X_(L) was determined using 15N HeteronuclearSingle Quantum Coherence Spectroscopy (HSQC) NMR methods.

The protein samples for NMR studies were uniformly labeled with ¹⁵N forscreening and uniformly double labeled with ¹⁵N and ¹³C for structurecharacterization according to the methods described in M. Jansson etal., J. Biomol. NMR, 7:131-141 (1996), and M. L. Cai et al., J. Biomol.NMR, 11:97-102 (1998).

Since the NMR experiments were performed at pH 7.2 in a pulse fieldgradient (PFG), HSQC with water flip back was used to maximize signalintensity (S. Grzesiek and A. Bax, J. Am. Chem. Soc., 115:12593-12594(1993); and G. S. Sheppard et al., Abstracts of Papers of the Amer.Chem. Soc., 213:81 (1997)) and to minimize destruction from the watersignal. HSQC spectra of Bcl-X_(L) were recorded prior to (freeBcl-X_(L)) and after the addition of the concentrated inhibitorsolution. The two spectra were compared to identify the chemical shiftsinduced by the additions of the inhibitor. Data processing was conductedusing nmrPipe, pipp and nmrDraw software (See, D. S. Garrett et al., J.Magn. Reson. Ser., B 95:214-220 (1991); and F. Delaglio et al., J.Biomol. NMR, 6:277-293 (1995)). Shifted peaks were cross-referenced tothe assignment table to reveal the residues affected by the presence ofgossypol compounds. The residues affected by the binding of (−)-gossypolare shown in FIGS. 11A and 11B, which show that (−)-gossypol binds tothe BH3 binding site in Bcl-X_(L).

To provide further insights into the binding of gossypol and itsenantiomers, additional embodiments of the present invention used NMRmethods to determine the 3D structure of gossypol in complex withBcl-X_(L) in solution. To that end, a set of triple resonance NMRexperiments were performed, and the backbone and sidechain resonanceassignments were assessed. The initial complexed structure, wascalculated with the X-PLOR program (Harvard University, Cambridge,Mass.) using a torsion-angle-dynamics protocol. The obtained 3Dstructure of Bcl-X_(L) in complex with gossypol was similar to the freeform of Bcl-X_(L) with the hydrophobic BH3 binding pocket formed by theα-helixes of the BH1, BH2, and BH3. To further refine the complexedstructure of Bcl-X_(L) and (−)-gossypol solved by NMR methods, thepresent invention further performed 4 ns molecular dynamics (MD)simulations. The average complex structure from the computationalsimulation from the last 50 ps is provided in FIG. 11C.

Similar HSQC experiments of Bcl-X_(L) were performed to obtain thebinding affinity of a gossypol compound by titrating a range ofinhibitor concentrations from 0.5 μM to 500 μM with a constantconcentration (100 μM) of ¹⁵N labeled Bcl-X_(L) protein. Changes in thechemical shifts of protein residues were monitored by ¹⁵N-HSQC spectra.Using chemical shift data for residue 146, a dose-dependent titrationcurve by gossypol was developed. FIGS. 28A and 28B show the titrationcurves of (−)-gossypol and (+)-gossypol with Bcl-X_(L) protein.

The present invention is not limited to any particular mechanism.Indeed, an understanding of any particular mechanism is unnecessary topractice (make and use) the compositions and methods of the presentinvention. Nonetheless, it is contemplated that the MD refined complexedstructures of the present invention confirm the important interactionsbetween (−)-gossypol and Bcl-X_(L) observed in the HSQC spectra obtainedfrom previous NMR experiments. Furthermore, MD refined structuresidentified by the present invention indicate that (−)-gossypol interactswith hydrophobic residues Y105 and L134 as well as with charged residuesG142 and R143. The present invention is not limited to any particularmechanism or mechanisms. Indeed, an understanding of any particularmechanisms is unnecessary to practice (make and use) the compositionsand methods of the present invention. Nonetheless, certain embodimentsof the present invention show that gossypol targets the hydrophobiccleft on the surface of Bcl-X_(L), which is a docking site for the BH3domain of pro-apoptotic proteins (e.g. Bid, Bad, Bax and Bak). Bindingof (−)-gossypol to this region alters the accessibility or bindingproperties of Bcl-X_(L) and Bcl-2 proteins to pro-apoptotic proteinsleads to the inhibition of the function of these proteins. Thus, in someembodiments, the present invention provides compounds that bind to thehydrophobic cleft on the surface of Bcl-2 and/or Bcl-X_(L) by, forexample, interacting with residues Y105, L134, G142, and/or R143. Thefunction of such compounds (whether natural or synthesized) can beassessed by testing the ability of the compound to disrupt or displacegossypol compound/Bcl-2/Bcl-X_(L) interactions.

Example 7 Expression of Bcl-2 Family Proteins in Human Cancer Cells

Several cancer cell lines (Table 16 and FIG. 7) that express variouslevels of Bcl-2 and/or Bcl-X_(L) proteins were selected in order to testthe activity of gossypol to inhibit proliferation of human cancer cells.

TABLE 16 Cancer Cell Line Bcl-2 expression Bcl-X_(L) expression Group IT47 breast cancer ± +++ MDA-453 breast − +++ cancer Group II MDA-435breast +++ ± cancer Group III MDA-231 breast +++ +++ cancer Group IVWI-38 normal − − SK-MEL-28 ± − melanomaExperiments using the cancer cell lines shown in Table 16 allowed forthe testing of several important features of gossypol as an anticanceragent. The activity and selectivity of gossypol in binding assays with anumber of cancer cell types that express various levels of Bcl-2 familyproteins indicates the range of cancer types that are suitablecandidates for treatment with gossypol. Testing gossypol in cancer cellswith high Bcl-2 and high Bcl-X_(L) expression levels indicates whetherinhibition of either protein alone was sufficient for induction ofapoptosis or whether simultaneous inhibition of both proteins achievesgreater anticancer potency. Assays using a number of cancer cell typesexpressing various levels of Bcl-2 family proteins indicate whethergossypol displays selectivity in cancer cells with both low Bcl-2 andlow Bcl-X_(L) expression.

Example 8 Investigations into the Mechanisms of Apoptosis Induced byGossypol

A series of biochemical assays were carried out to determine themechanisms of action of the gossypol compounds as small moleculeinhibitors of Bcl-2 family proteins (e.g., Bcl-2 and/or Bcl-X_(L)).Although an understanding of the mechanism is not necessary to practicethe present invention and the present invention is not so limited, it iscontemplated that an understanding of the mechanisms by which gossypolcompounds act on cells and tissues that overexpress Bcl-2 familyproteins is advantageous to the present invention.

Following the treatment of cells with inhibitors, qualitativeassessments of cell morphology were made to determine features relatedto apoptosis such as cellular swelling, nuclear swelling, membraneblebbing, vacuolization, and apoptotic body formation.

In some embodiments, DNA level detection of apoptosis was made bydetecting DNA fragmentation using TUNEL assays. When cells areundergoing apoptosis, apoptotic endonucleases not only affect cellularDNA by producing the classical DNA ladder but also generate free 3′-OHgroups at the ends of these DNA fragments. These groups were end-labeledby the TdT-FragFLTM DNA Fragmentation Kit (Oncogene, Boston, Mass.) thusallowing detection of apoptotic cells using molecular biology-based,end-labeling, histochemical, or cytochemical techniques. The rationaleof this assay is that terminal deoxynucleotidyl transferase (TdT) bindsto exposed 3′-OH ends of DNA fragments generated in response toapoptotic signals and catalyses the addition of biotin-labeled andunlabeled deoxynucleotides. Biotinylated nucleotides were detected usinga streptavidin-horseradish peroxidase (HRP) conjugate. Diaminobenzidinereacts with the labeled sample to generate an insoluble coloredsubstrate at the site of DNA fragmentation (See e.g., L. Lagneaux etal., Br. J. Haematol., 112:344-352 (2001); and K. Kitamura, Leukemia,14:1743-1750 (2000)).

In other embodiments, nuclei level detection methods (e.g., fluorescentdye Hoechst 33258 and propidium iodide staining) were used to quantifysigns of apoptosis in treated cells. Morphological changes in thenuclear chromatin of cells undergoing apoptosis were detected bystaining with 2.5 μg/ml of bisbenzimide Hoechst 33258 fluorochrome(Calbiochem, La Jolla, Calif.) followed by examination on a fluorescencemicroscope. A representative example of chromatin changes in cancercells with high expression levels of Bcl-2 and Bcl-X_(L) versus normalhuman fibroblast cells is provided in FIGS. 8A and 8B. In someexperiments, cells were double-stained with propidium iodide (PI, 2.5μg/ml) and Hoechst 33258 (2.5 μg/ml) to distinguish apoptotic cells fromnecrotic cells. Intact blue nuclei, condensed/fragmented blue nuclei,condensed/fragmented pink nuclei, and intact pink nuclei were consideredviable, early apoptotic, late apoptotic, and necrotic cells,respectively (See e.g., B. R. Gastman et al. Cancer Res., 60:6811-6817(2000); and N. Hail Jr., and R. Lotan, Cancer Epidemiol. BiomarkersPrev., 9:1293-1301 (2000)).

In still further embodiments, the present invention used cell leveldetection of apoptotic events by flow cytometry. Cells that hadundergone apoptotic events were detected by flow cytometry using aFACSCAN instrument (Becton Dickinson, Franklin Lakes, N.J.) with 488-nmlaser line and analyzed using CELL QUEST software (Becton Dickinson,Franklin Lakes, N.J.). Phosphatidylserine exposed on the outside of thecells (one of the major characteristics of apoptosis) was determined byTACSTM Annexin V-FITC Kit (Trevigen, Gaithersburg, Md.). Annexin V-FITCfluorescence is detected in FL-1, and propidium iodide was detected inFL-2. (Hail Jr., and R. Lotan, R. Cancer Epidemiol. Biomarkers Prev.,9:1293-1301 (2000)).

Apoptosis was further detected and quantified usingAnnexin-V-fluorescence assays. Cells were treated with differentconcentrations of (−)-gossypol or its enantiomers alone, docetaxelalone, or (−)-gossypol and docetaxel for 48 hrs. Cells were collectedand washed with PBS and stained with Annexin-V-Fluorescein and propidiumiodide (PI) following standard protocols. Stained cells were analyzedwith a flow cytometer (Becton Dickinson) using 488 nm excitation and a515 nm bandpass filter for fluorenscein detection, and a >600 nm filterfor PI detection. Representations of induction of apoptosis by gossypol(at various doses) in MDAMB-231 or T47D cells are shown in FIGS. 9, 10,29, and 30.

The expression and phosphorylation status of Bcl-2 proteins in cellstreated with gossypol compounds at various doses and times wasdetermined. In particular, the expression levels of Bcl-2, Bcl-X_(L),Bcl-X_(S), Bak, Bad, Bax, and Bid was determined by specific antibodiesusing Western blot analysis. Phosphorylation status for proteins such asBcl-2, Bcl-X_(L), and Bad was determined by Western blotting usingspecific antibodies that recognize the phosphorylated proteins.

The effects of gossypol on cellular mitochondria were examined byseveral methods (e.g., cytochrome c release and pore formation assays).Cells were treated with inhibitors for 24-48 hrs and cell fractionationwas performed as described in R. M. Kluck et al., Science, 275:1132-1136(1997) with some modifications as follows. Briefly, cells were harvestedand washed once with ice-cold PBS and resuspended in 1 ml ice-coldbuffer C (10 mM Hepes-KOH at pH 7.4, 0.42 M NaCl, 2.5% (v/v) glycerol,1.5 mM MgCl₂, 0.5 mM sodium EDTA, 0.5 mM EGTA, 1 mM dithiothreitol) anda protease inhibitor mix (PIM). The cell suspension was homogenized onice by passage 15 times through a 22 gauge needle. The homogenates werecentrifuged twice at 750 g for 10 min at 4° C. to remove nuclei. Thepost-nuclear supernatant fractions were centrifuged at 10,000 g for 15min at 4° C., and the resulting mitochondria-enriched pellets wereresuspended in 100 ml buffer C+PIM (cold). The post-mitochondrialsupernatant was centrifuged at 10,000 g for 1 hr at 4° C. to removemembrane contaminants and the resulting supernatant (soluble portion)was used for cytosolic cytochrome-c release detection (the pellet is themitochondrial membrane (heavy membrane proteins) portion). Solublefraction proteins and an equivalent amount of heavy membrane proteinswere subjected to SDS-PAGE and analyzed by Western blotting withantibodies against cytochrome c (Becton Dickinson, Franklin Lakes,N.J.), voltage-dependent anion channel (VDAC) (Calbiochem, La Jolla,Calif.), Smac, and AIF (apoptosis inducing factor) (Santa CruzBiotechnology, Santa Cruz, Calif.) analyses. These methods determinedapoptosis signaling following treatment of the test cells (e.g., cancercells) with gossypol compounds through three mitochondrial pathways:cyto-c release, Smac release, and AIF release.

Breast cancer cell lines MDA-231 and T47D were treated with either 5 or20 μM of gossypol for 24 hrs. FIG. 13 shows that cytochrome c wasreleased from the mitochondria into the cytosol after treatment with5-20 μM of gossypol in MDA-231 cells or T47D cells which providesfurther evidence of gossypol compound mediated apoptosis in these cells.Additional assays measured the activation of caspase-3, or the cleavageof PARP protein, a down-stream protein target of caspases. Treatmentwith (−)-gossypol also resulted in more cleavage of PARP protein underidentical doses (FIGS. 14 and 31).

Treatment of cells with 10 or 20 μM of gossypol for 8 hrs also provideda decrease in the mitochondrial transmembrane potential of the testMDA-231 cells as assessed by the cationic lipophilic cell-permeablefluorescent dye 3,3′-dihexy(−)-oxacarbocyanine iodide (DiOC₆) assays.The present invention is not limited to any particular mechanisms.Indeed, an understanding of any particular mechanism is unnecessary topractice (make and use) the present invention. Nonetheless, the dataindicate that gossypol compounds inhibit the anti-apoptotic functions ofBcl-2 proteins by suppressing the mitochondrial functions regulated bythese proteins.

In additional embodiments, the activation of caspases was determined bycollecting and washing treated cells with PBS and suspending the cellsin 25 mM HEPES (pH 7.5), 5 mM MgCl₂, 5 mM EDTA, 5 mM dithiothione, 2 mMphenylmethylsulfonyl fluoride, 10 g/mL pepstatin A, and 10 g/mLleupeptin after treatment. The treated cells were then lysed. The celllysates were clarified by centrifugation at 12000×g for 20 min at 4° C.Caspase-1, -2, -3, -6, -8, and -9 activity in the supernatant wasdetermined using the fluorogenic CaspACE Assay System (Promega Corp.,Madison, Wis.). Briefly, 50 mg aliquots of total protein, determined bythe bicinchoninic acid assay (Promega Corp.), were incubated with 50 mMsubstrate Ac-YVAD-AMC, Ac-VDVAD-AMC, Ac-DEVD-AMC, Ac-VEID-AMC,Ac-IETD-AMC, or Ac-LEHD-AMC at 30° C. for 1 hr. The release ofmethylcoumaryl-7-amine (AMC) was measured by excitation at 360 nm andemission at 460 nm using a fluorescence spectrophotometer (HitachiF-4500) according to G. Denecker et al., Cell Mol. Life Sci., 58:356-370(2001); and V. M. Kolenko et al., Apoptosis, 5:17-20 (2000)).

The effects of caspase inhibitors (e.g., Z-VAD-FMK, non-specific,Z-DEVD-FMK, caspases-3, -6, -7, -8, and -10, and Z-LEHID-FMK, caspase-9)on the activity of the gossypol compounds was determined using standardcaspase inhibitor assays. All of the caspase inhibitors used arecommercially available (Enzyme System Products, Livermore, Calif.).FIGS. 32A and 32B show caspase inhibitors in gossypol-mediated caspaseactivation and growth inhibition.

Example 9 Cell Survival Assay

Cells were seeded in 24 or 96-well-plates and gossypol compounds wereprepared at 2-10 fold dilutions in suitable medium. Inhibition of cellviability was determined by treating the cells with the gossypolcompounds for 24 hrs. Cell viability was then determined by thetrypan-blue assays. Inhibition of cell growth was determined by treatingcells with gossypol compounds for 3-6 days. Cell inhibition wasdetermined using XTT. In some embodiments, MTT assays are used todetermine cell inhibition.

In one embodiment, to evaluate cell proliferation, soluble XTT (Sodium,3′-(1-((phenylamino)-carbonyl)-3,4-tetrazolium)-bis(4-methoxy-6-nitro)benzenesulfonic acid hydrate (Polysciences, Inc., Warrington, Pa.)assays were performed on cells growing in 96-well plates. After 5 daysof incubation, when the control untreated cells reached confluence, 50μl of XTT (1 ng/ml) was added to each well and incubation continued for4 hrs at 37° C. Absorbance at 450 nm was measured using a Dynatech ModelMR700 device (Dynatech Laboratories Ltd. Billinghurst, United Kingdom).The percentage of surviving cells was defined as mean absorbance oftreated wells/mean absorbance of untreated wells×100.

MTT assays provide a fast, accurate, and reliable method for obtainingcell viability measurements. MTT assays are simple and colorimetric.Numerous laboratories have utilized MTT assays for toxicity studies (Seee.g., Kuhlmann et al., Arch. Toxicol., 72:536 (1998)). Briefly,mitochondria produce ATP to provide sufficient energy for the cell. Inorder to do this, the mitochondria metabolize pyruvate to produce acetylCoA. Within the mitochondria, acetyl CoA reacts with various enzymes inthe tricarboxylic acid cycle resulting in subsequent production of ATP.Succinate dehydrogenase is one of the enzymes measured by MTT assays.The MTT compound (3-(4,5-dimethylthiazol-2-yl)-2 diphenyl tetrazoliumbromide) is a yellow substrate that is cleaved by succinatedehydrogenase to form a purple formazan product. The colorimetricresponse of MTT (yellow to purple) thus identifies changes inmitochondria function. Nonviable cells are unable to produce the MTTformazan product; therefore, the amount of purple MTT formazan productproduced directly correlates to the quantity of viable cells. Absorbanceat 540 nm is used to measure the amount of formazan product.

The present invention is not limited to any particular mechanisms.Indeed, an understanding of any particular mechanism is unnecessary topractice (make and use) the present invention. Nonetheless, it iscontemplated that FIG. 12 shows that, in certain embodiments,(−)-gossypol is 2 times more potent than (+)-gossypol and is 5-10 timesmore potent than (+)-gossypol in inhibition of cell growth in breastcancer cell lines with high levels of Bcl-X_(L). The data suggest that(−)-gossypol is more potent than (+)-gossypol, and is more selectivebetween cancer cells with high levels of Bcl-X_(L) expression and canceror normal cells with low levels of Bcl-X_(L) such as DU-145 or WI-38.

Example 10 Colony-Formation in Soft-Agarose

The soft-agar colony formation assays were used to directly measure thetransforming ability of cancer cells. These assays are known tocorrelate well with in vivo tumorigenicity.

Experiments were conducted using combination treatments to assess theapoptotic effects or inhibition of cell proliferation obtained byadministration of Bcl-2 inhibitors in combination with knownchemotherapeutic agents. In preferred embodiments, these results wereused to select synergistic agent combinations.

Cells were trypsinized and resuspended in 1 ml 0.33% top agarose (10,000cells/ml) on 1% bottom agarose. The next day, 1 ml aliquots of regularmedium containing (−)-gossypol were gently layered to the top of theagarose and incubation continued for 2 weeks. The number of coloniesgreater than 80 μm in diameter were counted using a Bausch and LombImage Analysis System (Omega 3800). FIG. 33 shows a representativeexample of inhibition of soft agar colony formation in theseexperiments.

Example 11 In Vivo Antitumor Activity Studies

Preliminary in vivo studies showed that gossypol is a potent Bcl-X_(L)inhibitor, and that it exhibits significant anti-tumor activity aloneand in combination with additional conventional anticancer agents (e.g.,docetaxel). Preferred embodiments of the present invention provide invivo anti-tumor efficacy and selectivity studies using human cancerxenograft models.

The results of in vitro experiments can be compared to in vivo toxicitytests to extrapolate live animal conditions. Typically, toxicity from asingle dose of a substance is assessed. In some embodiments, animalswere monitored over 14 days for any signs of toxicity (increasedtemperature, breathing difficulty, death, etc.). Typically, the standardof toxicity is the measurement of the maximal tolerated dose (MTD). TheMTD is the highest dose that results in no lethality/tissue abnormalityor causes them to gain 10% less weight than control animals.

The determination of the MTD occurred by exposing test animals to ageometric series of doses under controlled conditions. Other testsincluded subacute toxicity testing, which measures the animal's responseto repeated doses of gossypol compounds (or one or more conventionalanticancer agents) for no longer than 14 days. Subchronic toxicitytesting involved testing of a repeated dose for 90 days. Chronictoxicity testing is similar to subchronic testing but lasts for morethan 90 days. In vivo testing was conducted to determine toxicity withrespect to certain tissues. For example, in some embodiments of thepresent invention, tumor toxicity (e.g., effect of the compositions ofthe present invention on the survival of tumor tissue) was determined(e.g., by detecting changes in the size and/or growth of tumor tissues).

In order to design optimal dose schedules for gossypol therapies,studies first utilized human breast cancer cell lines MDA-231 (clone2LMP), and then additional tumor xenograft models such as MDA-435(LCC6), and T47D. MDA-231 expresses high levels of both Bcl-2 andBcl-X_(L); MDA-435 expresses high levels of Bcl-2 but low levels ofBcl-X_(L); T47D expresses low levels of Bcl-2 but high levels ofBcl-X_(L). Among all of the 7 human breast cancer cell lines examined,no cell line had both low Bcl-2 and low Bcl-X_(L). The human prostateDU-145 mice xenograft model, however, expresses low levels of both Bcl-2and Bcl-X_(L) and was thus used as a negative control in someembodiments to test the specificity of gossypol compounds and gossypolderivatives.

In one embodiment using the MDA-231 model, a series of comprehensivedose and schedule investigations was performed to determine: 1) theminimal active dose, defined as inhibition of tumor growth by 50% ascompared to control with a statistical confidence level of 95%; 2) theoptimal schedule of administration in inhibition of tumor growth whilenot causing toxicity defined as weight loss of more than 25%; 3) theeffect of gossypol compounds on large tumors (more than 2,000 mm³); 4)how long could gossypol can be administered to mice in the control groupwithout causing morbidity or mortality (e.g., weight loss).

After identifying optimal doses and dosing schedules, testing ofcombination therapies with at least one additional conventionalchemotherapeutic agent was conducted, including, but not limited to, 1)doxorubicin (4 mg/kg); 2) 5-FU (10 mg/kg); 3) VP-16/etoposide (40mg/kg); and 4) cyclophosphamide (100 mg/kg); and 5) cisplatin (10mg/kg). As a positive control, TAXOTERE was used at a dose of 7.5 mg/kg.Control group mice received either no treatment or vehicle alone. Toachieve statistic significance, a minimum of 10 mice per group was usedin the combination regimes.

For all tests, mice were randomized and then injected in the fat padwith 1-5×10⁶ cells prepared in serum-free medium. The animals weremeasured and weighed twice each week during the treatment period,followed by twice a week measurements for an additional 4-6 weeks. Agross visual necropsy of each animal was performed at death or terminalsacrifice. A representative example of in vivo animal testing data ofgossypol either alone or in combination with TAXOTERE is provided inFIG. 15.

The rate of apoptosis in tissues was determined using the TUNEL method(terminal deoxyribonucleotidyl transferase (TdT)-mediateddUTP-digoxigenin nick end labeling). The TUNEL, method is extremelysensitive (See. Y. Gavrieli et al., J. Cell Biol., 119:493-501 (1992);and M. Dowsett et al., Cytometry, 32:291-300 (1998)). Paraffin-embeddedtissues were sectioned, and slides were incubated in labeling buffer for5 min. then placed in a humid chamber with TdT, dNTP mix, and Mg⁺⁺ inlabeling buffer. Strepavidin-Horseradish Peroxidase was applied ontoeach sample for 10 min., the samples were washed and counter stainedwith methyl green or hematoxylin. The rate of apoptosis was calculatedby counting and dividing the number of apoptotic cells by the totalnumber of cells seen per light microscopy field at 40× magnification,and is expressed by percent.

Example 12 Drug Interactions between Gossypol and Docetaxel

The present invention is not limited to any particular mechanisms.Indeed, an understanding of any particular mechanism is unnecessary topractice (make and use) the present invention. Nonetheless, it iscontemplated that, in certain embodiments, gossypol compounds are likelyto be used in combination with standard chemotherapeutic agents.Although gossypol alone inhibited cell proliferation, combinationtreatments resulted in enhanced effects (e.g., greater induction ofapoptosis in target cells). Experiments show that (−)-gossypol acts insynergy with docetaxel (TAXOTERE, or TXT), or paclitaxel (TAXOL) toinhibit the growth of breast cancer cells such as MDA-MB-231 (FIG. 34),or MCF-7 (FIG. 16).

Isobologram analyses (See, T. C. Chou and P. Talalay, Adv. EnzymeRegulation, 22:27 55 (1984)), are widely used to determine synergism oftwo or more drugs when used in combination. In some embodiments,isobologram analyses show that the combination of TAXOTERE with(−)-gossypol resulted in significant synergy, with a Combination Index(CI) of 0.7 and 0.5, and a Dose Reduction Index (DRI) of 1.94 and 2.34for administration of TAXOTERE with either 4 μM or 5 μM of (−)-gossypol,respectively. Briefly, FIGS. 17A and 17B show the in vitro effects of(−)-gossypol in combination with various doses of TAXOL in MDA-MB-231based growth assays, wherein: CI value<1 indicates synergistic effects;CI=1 indicates additive effects; CI value>1 indicates antagonisticeffects; DRI>1.0 indicates synergistic effects. Treatment of MDA-MB-231cells with (−)-gossypol significantly potentiated the cells' response toTAXOL mediated cytotoxicity and resulted in further reductions in cellsurvival from controls. Thus, in some embodiments, gossypol compoundsprovide a synergistic effect when used in combination with cytotoxicagents such as taxanes (e.g., TAXOTERE). The present invention is notlimited to any particular mechanisms. Indeed, an understanding of anyparticular mechanism is unnecessary to practice (make and use) thepresent invention. Nonetheless, the data indicate, in some embodiments,that gossypol compound mediated inhibition of cell proliferation isenhanced when combined with chemotherapeutic agents and that thecombined effect are specific for gossypol. Other chemotherapeutic drugswere also tested in combination with gossypol.

The effect of gossypol alone on the erythromycin breath test (ERMBT), aphenotypic test for CYP3A4 metabolism, was evaluated by comparingbaseline ERMBT levels at baseline and after 1-week pretreatment withgossypol (See, e.g., P. Watkins, Pharmacogenetics, 4:171-184 (1994); andJ. Hirth et al., Clin. Cancer Res., 6:1255-1258 (2000)). ERMBT assaysproduce a measurement of the percentage of ¹⁴C exhaled per hour, that isusually approximated using the Normal distribution (See, D. Wagner,Clin. Pharm. Therap., 64:129-130 (1998)). The mean levels of ¹⁴Cexhaled/hr were compared using a standard (alpha=0.05), two-sided,paired t test. Using estimates from previous work (J. Hirth et al.,Clin. Cancer Res., 6:1255-1258 (2000) for the baseline mean ¹⁴Cexhaled/h (n=21, mean=2.41), its standard deviation (SD=1.08),correlation of ERMBT measurements over time (r=0.81), and assumingconstant variance at each measurement, the current example with datafrom 30 subjects has 96% power to detect a 20% decrease (2.41 to 1.93),and 81% power to detect a 15% decrease (2.41 to 2.05) in mean ERMBTlevels. The mean, standard deviation, and range of ERMBT values wastabulated and reported, along with the significance of the paired ttest.

Example 13 Pharmacokinetic Description of Docetaxel in Patient Samples

Blood is drawn for a pharmacokinetic description of docetaxel whenadministered in combination with gossypol using an optimal samplingstrategy (See, P. Baille et al., Clin. Cancer Res., 3:1535-1538 (1997)).Blood is drawn directly before the end of infusion (EOI) of docetaxel,at 0.25, 0.75, 3.00, 6.50, and at 24 hrs following EOI. All samples areassayed at the same time. A Bayesian criterion is used to calculate thedocetaxel plasma concentration area under the curve (AUC) based uponmeasured drug levels and population pharmacokinetic parameterspreviously estimated (See, R. Bruno et al., J. Clin. Oncol., 16:187-196(1998)) for docetaxel alone, using NONMEM software (S. L. Beal and L. B.Shener, Nonlinear Mixed Effects Model Users Guides (San Francisco,Calif., NONMEM Project Group, University of California at San Francisco)(1999)). Clearance (CL) is directly estimated by fitting the nonlinearmixed effects model (R. Bruno et al., J. Clin. Oncol., 16:187-196(1998)). The AUC is calculated as a function of dose and clearance,defined as AUC=dose/CL. ERMBT values from baseline and 1-week followinggossypol pretreatment are plotted separately against Clearance. Ordinaryleast squares regression is used to defined the relationship betweendocetaxel CL and the ERMBT or the natural logarithm of ERMBT. Theestimated slopes are displayed along with previously published valuesfor single treatment docetaxel CL (J. Hirth et al., Clin. Cancer Res.,6:1255-1258 (2000) in order to describe any differences in docetaxel CLwhen administered in combination with gossypol versus single agentadministration.

Example 14 Expression of Bcl-2 Family Protein in Patient Samples

The expression of Bcl-2 and Bcl-X_(L) in tissue samples collected inparaffin blocks was assayed using standard immunohistochemical (IHC)assay methods. IHC results were dichotomized and tabulated to show thepercentage of patients expressing these markers. Results were tabulatedagainst anti-tumor response. Chi-square statistic and Fisher's exacttests were performed to assess the relationship between expression andanti-tumor response, depending on the size of the cell counts in theresulting table.

In some embodiments, tissues were fixed in 4% buffered formalin,processed, and embedded in paraffin according to the normal scheduleused in the laboratory. From each block, 5 μm-thick sections were cut oncoated slides and dried overnight at 37° C. The sections weredeparaffinized in xylene and rehydrated through graded concentrations ofethanol to distilled water. Sections to be stained with antibodiesagainst Bcl-2, Bax, Bcl-X_(L), and Bag-1 were pretreated by boiling themfor 20 min in citrate buffer (pH 6.0) or pretreated by digestion in 0.5%trypsin (pH 7.2) at 37° C. for 30 min. Immunohistochemical stainingswere performed using commercial Elite ABC kits (VECTASTAIN, VectorLaboratories, Burlingame, Calif.). Blocking serum was applied for 15 minfollowed by overnight incubation with the diluted primary antibody:Bcl-2, 1:200 (clone 124, DakoCytomation, Inc., Carpinteria, Calif.);Bax, 1:100 (clone 2D2; Zymed Laboratories, Inc., South San Francisco,Calif.); Bcl-X_(L), 1:50 (clone 2H12; Zymed); Bag-1, 1:200 (monoclonalmouse (12), (Santa Cruz Biotechnology, Inc., Santa Cruz, Calif.); thesections were then incubated with the biotinylated secondary antibodyand the peroxidase-labeled ABC solution (VECTASTAIN) for 30 min each.All of the dilutions were made in PBS (pH 7.2), and all of theincubations were performed in humid chambers at room temperature.Between each step in the staining procedures (except before incubationwith the primary antibody), the slides were rinsed three times in PBS.Bound peroxidase was visualized in all of the slides with a3-amino-9-ethyl-carbazole solution (0.2 mg/ml in 0.05 M acetate buffercontaining 0.03% perhydrol (pH 5.0); AEC; Sigma Chemical Co., SaintLouis, Mo.) at room temperature for 15 min. The sections were lightlycounterstained in Mayer's hematoxylin and mounted in Aquamount Mountant(BDH Ltd., Poole, United Kingdom). For each antibody, a known positivecase of cancer was included in every staining batch as a positivecontrol. Cells were considered positive when a distinct cellularmicropunctate pattern of staining was seen, except for Bag-1, for whichnuclear staining was also accepted. The percentage of immunoreactivecells was evaluated as the amount of positive tumor cells per all of thetumor cells on the section. All of the stained sections were scored bytwo investigators, who were blinded to the clinical data. Median valueswere then used as the cut-points for low and high expression. Spearmancorrelation coefficients were calculated for the investigated tumorbiological factors.

In some embodiments, 5 μm-thick sections of the formalin-fixed,paraffin-embedded tumors were immunostained using monoclonal Bcl-2(1:160) (DakoCytomation), polyclonal Bax (1:1500) (PharMingen, SanDiego, Calif.), and polyclonal Bcl-X (1:1500) (PharMingen). Anavidin-biotin enzyme complex kit (Signet Laboratories Inc., Dedham,Mass.) with steam antigen retrieval was used in combination with theautomated TechMate 1000 immunostaining system (Biotek Solutions Inc.,Santa Barbara, Calif.). Hematoxylin and eosin were used ascounterstains. Sections of tonsil were used as positive controls forBcl-2, while normal breast ducts and lobules were used as positivecontrols for Bax and Bcl-X_(L). In some embodiments, negative controlshad primary antibody replaced by buffer. The immunostaining was recordedas 0 to 3+ according to stain intensity, distribution in cytoplasmand/or nucleus, and percentage of cancerous cells that stained positive.Tumors with less than 5% of carcinoma cells staining with 1+ positivitywere considered negative.

In some embodiments, the percentage of nuclear and cytoplasmicimmunostain for the antigens (Bcl-2, Bax, Bcl-X_(L)) were quantitatedusing the CAS 200 image cytometer (Becton Dickinson Cellular ImagingSystems, San Jose, Calif.). The immunoperoxidase/diaminobenzidineprocedure stained positive nuclei and cytoplasm brown and negative areasblue and pink, respectively. At 620 nm, brown, blue, and pink absorb,providing a measure of total nuclear and cytoplasmic area. At 500 nm,thresholds were set so that only the brown stained areas absorbed,allowing the immunopositive nuclear and cytoplasmic areas to be measuredindependently. Comparison with the 620 nm mask gave the percent positivearea immunostained (PPA). Fifteen fields were analyzed in each slide soas to minimize the standard deviation. Areas were isolated from adjacentstroma by using the scene segmentation function, which allows theoperator to precisely define portions of the image to be analyzed. Thisprevents positive staining of non-cancerous tissue elements such aslymphocytes, from being included in the PPA. Computer generatedhistograms showed PPA on the vertical axis and nuclear/cytoplasmicoptical density (OD) on the horizontal axis. The OD of the chromogen wasproportional to the amount of immunostain. The computer calculated thenumber of fields, total nuclear/cytoplasmic area analyzed, and PPA asaverages of intensity of immunostaining. A ratio was then obtained ofthe PPA Bcl-2 divided by the PPA of Bax and Bcl-X_(L). Basic descriptivestatistics, including means, standard deviations, and ranges were usedto characterize the study sample. Pearson's correlation coefficientswere used to explore the association between continuous measures.P-values less than 0.05 were considered statistically significant.

In some embodiments, the level of target antigen expression wasquantified as follows: samples with more than 50% positive cells wereclassified as strongly positive (++), while samples with 5-50% positivecells were classified as moderately positive (+), and samples with fewerthan 5% positive cells were classified as negative (−) (See, Alderson etal., Cancer Res., 999-1001 (1995)). Areas free of necrosis and capillaryendothelial proliferation were chosen for analysis. The infiltrativeedge of the tumor where normal neurons and glia are surrounded byneoplastic cells was also excluded. An eyepiece grid was used forcounting at a magnification of 400×. Three high-power fields werecounted for each sample and antigen. The correlation between theexpression of different proteins was analyzed with the Chi-square testof independence with Yates' correction for continuity (P, 0.05).

Example 15 Peripheral Blood Lymphocytes Studies

Blood samples collected from study participants before study treatment,on day 8 (following 1 week gossypol pretreatment), and at week 9 (aftercompletion of one cycle of gossypol plus docetaxel) are used forexploratory studies involving peripheral blood lymphocytes (PBL) andcirculating epithelial cells (CEC). Using fluorescent activated cellsorting techniques (FACS), PBLs are characterized for their expressionof Bcl-2 and Bcl-X_(L) before and after gossypol administration. Themean number of PBLs with expression and its standard deviation will bereported at each time point. Using an immunomagnetic separation methodpreviously described (See, T. Walker et al., Proc. Amer. Soc. Clin.Oncology, 19:54b (2001)) the feasibility of finding CECs is determinedfor each patient. The mean number of CECs per 10 ml of blood collectedand its standard deviation across patients at each time point will bereported.

Example 16 Administration of (−)-Gossypol in Combination withConventional Chemotherapeutic Agents in a Mouse Xenograft Model

This example describes experiments conducted to evaluate the in vivoantitumor efficacy of (−)-gossypol in human xenograft models eitheralone or in combination with chemotherapy. Docetaxel (TAXOTERE or TXT)was administered as described herein.

In this experiment, male 5 to 6 week old NCI athymic NCr-nu/nu nude micewere inoculated subcutaneously in the mammary fat pad on each side withan injection of about 1×10⁶ MDA-MB-231 (2LMP) in 0.3 ml serum freemedium (SFM). The best xenograft recipients were used. Treatments beganwhen tumors averaged about 50 mm³ (5-7 mm in diameter, usually at day7). Treatments ran for 4 weeks with a 2 month follow up period.Resolution of gossypol enantiomers was carried out as describedpreviously. (−)-Gossypol compounds were dissolved in ethanol and dilutedwith final 10% ethanol in PBS before injection. All oral administrationsof (−)-gossypol and 10% alcohol were given by gavage.

Test animals were divided into cohort groups of 8 animals into thefollowing treatment groups: Control (Group 1); Vehicle control (Group2), daily oral administration of 10% alcohol only; (−)-gossypol (Group3), 7.5 mg/kg administered orally per day for 4 weeks; (−)-gossypol(Group 4), 15 mg/kg administered orally per day for 4 weeks;(−)-gossypol (Group 5), 30 mg/kg administered orally per day for 4weeks; docetaxel (or TAXOTERE, TXT) (Group 6), 7.5 mg/kg administeredintravenously once per week for 4 weeks; (−)-gossypol plus TXT (Group7), 7.5 mg/kg (−)-gossypol administered orally per day for 4 weeks, plus7.5 mg/kg TXT administered intravenously once per week for 4 weeks;(−)-gossypol plus TXT (Group 8), 15 mg/kg (−)-gossypol administeredorally per day for 4 weeks, plus 7.5 mg/kg TXT administeredintravenously once per week for 4 weeks; and (−)-gossypol plus TXT(Group 9), 30 mg/kg (−)-gossypol administered orally per day for 4weeks, plus 7.5 mg/kg TXT administered intravenously once per week for 4weeks.

During the treatment course, tumor sizes and animal weights weremeasured 3 times per/week for each animal. Following treatment, tumorsizes were measured 2 times per/week, and animal weights once per/week.Tumor and weight observation were made without knowledge of the animal'streatment group. A representative example of in vivo xenograft basedexperiments used to investigate the anti-tumor activity of (−)-gossypolin combination with docetaxel is provided in FIG. 18. Docetaxeltreatment started at day 7 and was given i.v. at a weekly dose of 7.5mg/kg for 3 weeks. The results show that treatment by docetaxel alone insub-optimal dose (7.5 mg/kg weekly) inhibited tumor growth. But, thecombination of gossypol at three doses level (7.5, 15, and 30 mg/kg,respectively) with docetaxel achieved a much greater activity ininhibition of tumor growth. In the group of 10 mice treated with acombination therapy, 3 out of 10 mice (6 tumors) had complete tumorregression. Overall, there was more than 90% of inhibition in tumorgrowth in the combination group as compared to the group control.Statistical analyses were performed using a mixed-effects repeatedmeasures model which accurately takes into account the correlationwithin an animal over time, and between tumors within an animal. Thedata was modeled using the natural logarithm of tumor volume.Comparisons of the growth rates of animals administered (−)-gossypolalone and docetaxel alone were performed. Table 17 provides an exampleof one such comparison with (−)-gossypol at 7.5 mg/kg and docetaxel.

TABLE 17 Tumor Growth Tumor Growth Inhibition Delay Treatment (T/C %) (T− C Days) Radiation 77.7 8.5 (−)-gossypol 98.6 0 Radiation +(−)-gossypol 12.6 54.5Table 17 shows a comparison of the tumor growth rate between(−)-gossypol 7.5 mg/kg, docetaxel 7.5 mg/kg, and the combination;P-values for the linear contrast are reported. Findings werestatistically significant findings when p<0.05.

In a subset of the mice treated with either Docetaxel alone or acombination therapy, a second round of treatments with the same regimenwas initiated at day 45. The average tumor volume before the secondcycle treatment was about 2000 mm³. Tumors in the Docetaxel alonetreated group continued to grow and all the mice were sacrificed due tothe tumor burden. The combination treatment groups displayed tumorregression and total 50% reduction of tumor volume (FIG. 19). The dataclearly shows that (−)-gossypol was very effective in potentiatingdocetaxel in combination treatments even at a doses where it is lesseffective when administered as a single agent.

In yet another embodiment, the in vivo anti-tumor activity of(−)-gossypol was investigated in non-small cell lung carcinoma line A549cells. A549 cells express high levels of Bcl-X_(L). FIG. 20 shows theresults from these experiments. Briefly, in FIG. 20, gossypol wasadministered in combination with paclitaxel (TAXOL), wherein paclitaxelwas administered at a weekly dose of 15 mg/kg with daily p.o.administration of (−)-gossypol at 7.5 mg/kg.

Example 17 Treatment of Squamous Head and Neck Cancer with GossypolCompounds

The following experiments were conducted to determine the suitabilityand efficacy of gossypol compounds, e.g., (−)-gossypol, totherapeutically treat squamous head and neck cancers. The results aresummarized in FIGS. 21, 22, 23, and 24A-24C.

Ten squamous cell carcinoma cell lines established at the University ofMichigan (UM-SCC) and three human fibroblast lines were grown inDulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetalbovine serum. UM-SCC cell lines originated from the larynx (n=2;UM-SCC-12, -23), oral cavity/oropharynx (n=5; UM-SCC-1, -6, -14A, -74B,-81B), hypopharynx (n=1; UM-SCC-22A) and metastases from laryngealcancers (n=2; UM-SCC-17B, -25). Human fibroblast cell lines originatedfrom surgical specimens (fibroblast cell lines 2 and 3) and neonatalforeskin samples (fibroblast cell line 1).

Cell-Growth Inhibition Assays (MTT Assays)

Logarithmically growing cell lines were cultured, washed, counted, andplated at 5,000-15,000 cells per well in duplicate wells of 96-wellplates and incubated in DMEM overnight. The following day, serialdilutions were made from stock solutions of racemic, (+)-, or(−)-gossypol to achieve the desired concentrations. All experimentalconditions were performed with 5 replicates. The sample plates wereincubated for 6 days in 300 μL of DMEM containing gossypol or solventcontrols. MTT assays were then performed according to the manufacturer'sprotocol (Roche Diagnostics, Mannheim, Germany). The MTT assay measurescell survival based on mitochondrial conversion of MTT from a solubletetrazolium salt into an insoluble colored formazan precipitate, whichis dissolved in dimethyl sulfoxide and quantitated by spectrophotometry.(M. C. Alley et al., Cancer Res., 48:589-601 (1988)). Percent absorbancerelative to control was plotted as a linear function of drugconcentration. The 50% inhibitory concentrations (IC₅₀s) were identifiedas the concentration of drug required to achieve 50% growth inhibitionrelative to untreated control populations. The cell growth inhibitioncurves by (−)-gossypol in a panel of squamous cell carcinoma cell lines(UM-SCC) and three fibroblast cell lines are provided in FIG. 21.

Western Blot Analysis

Proteins were harvested during log phase growth by lysing cells in theflask using a solution of phosphate buffered saline (PBS) (BioWhittaker,Walkersville, Md.) containing 1% NP-40 (Sigma; St. Louis, Mo.), 1 mMPMSF (Sigma) and 1 tablet of a cocktail of protease inhibitors(Boehringer Mannheim, Germany) per 100 ml of PBS. The protein extractswere quantified using a calorimetric assay (Bradford Reagent) (BioRad,Hercules, Calif.). Thirty micrograms of protein were resolved on 12%Tris-glycine sodium dodecyl sulfate polyacrylamide gels (115V) underdenaturing conditions and transferred to Hybond-P PVDF membranes(Amersham Pharmacia Biotech, Buckinghamshire, England) at 30V overnight.Membranes were blocked in Tris-buffered saline containing 5% nonfat drymilk at room temperature for 1 hour and then incubated with primaryantibody. Primary antibodies included murine anti-human Bcl-2oncoprotein (124) monoclonal antibody (Dako, Glostrup, Denmark), murineanti-Bcl-xL (YTH-2H12) monoclonal antibody (Trevigen Inc., Gaithersburg,Md.) and rabbit anti-Bcl-XS (Ab-1) polyclonal antibody (OncogeneResearch Products; Boston, Mass.). Equivalency of protein loading wasevaluated using either murine anti-actin monoclonal antibody (ChemiconInternational, Temecula, Calif.) or murine anti-GAPDH monoclonalantibody (Chemicon). Membranes were then incubated with a secondaryhorseradish peroxidase-conjugated anti-mouse (or rabbit) antibody(Amersham Pharmacia Biotech) and analyzed using EnhancedChemiluminescence Plus reagent (Amersham Pharmacia Biotech).Densitometry readings for three independent blots were taken usingAlphaEase software version 5.5 (Alpha Innotech Corp., San Leandro,Calif.) for statistical analysis.

Expression levels of Bcl-2, Bcl-X_(L) and Bcl-X_(S) proteins in a panelof squamous cell carcinoma cell lines (UM-SCC) and one fibroblast cellline are provided in FIG. 22. FIG. 23 plots the relationship between theratio of Bcl-X_(L) and Bcl-X_(S) and the IC₅₀ values (concentrationrequired to inhibit 50% of cell growth related to untreated controlcells) of (−)-gossypol in a panel of squamous cell carcinoma cell lines(UM-SCC) and one fibroblast cell line.

Apoptosis Assays

Apoptosis of UM-SCC cell lines following (−)-gossypol treatment wasquantitatively detected by enzymatic labeling of DNA strand breaks usingterminal deoxynucleotidyltransferase (TdT) and Alexa Fluor-BrdUTP, knownas the TdT-UTP nick end-labeling (TUNEL) assay by flow cytometry. Cellswere exposed to (−)-gossypol for 48 hours, harvested, fixed and TUNELstained according to the manufacturer's protocol (Molecular Probes Inc.,Eugene, Oreg.). Ten thousand cells were analyzed per sample usingexcitation of Alexa Fluor at 488 nm. Apoptotic index (AI) was defined aspercent of apoptotic cells in the treatment population minus that in thevehicle control population.

The results on 4 representative squamous cell carcinoma cell lines(UM-SCC-1, UM-SCC-6, UM-SCC-12, UM-SCC-14A) and two fibroblast celllines (fibroblast 1 and 2) are provided in FIGS. 24A, 24B, and 24C,respectively.

Example 18 Clonogenic Assay of Administration of (−)-Gossypol andRadiation Therapy

PC-3 cells obtained from the American Type Culture Collection and theNational Cancer Institute were cultured in improved minimal essentialmedium (IMEM) (Biofluids, Rockville, Md.) with 10% fetal bovine serum(PBS) and 2 mM L-glutamine. Cultures were maintained in a humidifiedincubator at 37° C. and 5% CO₂. Resolution of gossypol enantiomers wascarried out as described in Example 3. Gossypol compounds were firstdissolved in ethanol and diluted with sterile water within 5 min to afinal ethanol concentration of 10% prior to each administration.

The PC-3 cells were used in a standard clonogenic assay to investigatethe effects of gossypol compounds, e.g., (−)-gossypol, on the cell'sresponse to subsequent radiation therapy. Briefly, at day 1, 200 to10,000 PC-3 cells per well were plated into 6 well plates using standardtechniques. The cells were then treated with 1-5 μM (−)-gossypol andthen exposed to 2 to 8 Gy, 300 keV, X-ray irradiation within 1 h. One mlof complete medium was added per well on Day 5. After 10 to 12 days inculture, the plates were stained with crystal violet and colonies withover 50 cells were counted using a ColCount (Oxford Optronix Ltd.,Oxford, U.K.) colony counter. For each combination treatment, parallelanalyses with each agent alone were also performed.

The data generated during the course of development of the presentinvention show that (−)-gossypol sensitizes PC-3 cells to radiationtherapy in the clonogenic assay tested. The cell survival curves wereplotted with linear-quadratic model as shown in (FIGS. 35A and 35B).Briefly, FIG. 35A shows the in vitro effects of (−)-gossypol incombination with various doses of radiation on PC-3 clonogenic assays,wherein: CI=Combination index; CI value<1 indicating synergisticeffects; CI=1 indicating additive effects; CI value>1 indicatingantagonistic effects; DRI=Dose Reduction Index; DRI>1.0 indicatingsynergistic effect. Treatment of PC-3 cells with (−)-gossypolsignificantly reduced PC-3 cells' resistance to accompanying radiationtherapy, resulting in 10- and 20-fold reductions in colony formationfrom controls at doses of 6 Gy and 8 Gy, respectively. The isobologramanalyses (See, T. C. Chou and P. Talalay, Adv. Enzyme Regulation,22:27-55 (1984)), widely used analyses used to determine synergism, showthat the combination of radiation with (−)-gossypol resulted insignificant synergy, with the Combination Index (CI) of 0.27 and 0.34,and the Dose Reduction Index (DRI) of 6.1 and 4.3 for administration of8 Gy radiation with either 5 μM or 4 μM gossypol, respectively. Theresults demonstrate that (−)-gossypol sensitizes PC-3 cells to X-rayirradiation in a dose-dependent manner.

Example 19 Administration of Gossypol Compounds and Radiation Therapy inan In Vivo Mouse PC-3 Xenograft Model

In this experiment, 34 male 5 to 6 week old NCI athymic NCr-nu/nu nudemice were inoculated in each flank with an injection of about 5×10⁶ PC-3cells. The best 25 xenograft recipients were used. Tumors averaged about50 mm³. (−)-Gossypol was first dissolved in ethanol and diluted withsterile water within 5 min to a final ethanol concentration of 10% priorto each administration. Irradiated test animals were restrained, placedunder the X-ray head, and covered with lead shields to ensure that thetumor area was exposed to radiation. All oral administrations of(−)-gossypol and 10% alcohol were given by gavage (Table 18).

The 25 best xenograft mice were divided into 5 experimental groups (5mice per group) as follows: Vehicle control (Group 1), daily oraladministration of 10% alcohol; radiation only (Group 2), 2 Gyadministered 5 times/week for 2 weeks, and daily oral administration of10% alcohol; radiation plus gossypol (Group 3), 2 Gy administered 5times/week for 3 weeks, and 10 mg/kg of (−)-gossypol administered orallyevery day for 4 weeks; gossypol only (Group 4), 10 mg/kg (−)-gossypoladministered orally every day for 4 weeks; control (Group 5), notreatment. During the treatment course, tumor sizes and animal weightswere measured 3 times per/week for each animal. Following treatment,tumor sizes were measured 2 times per/week, and animal weights onceper/week. Tumor and weight observations were made without knowledge ofthe animal's treatment group.

Treatment with (−)-gossypol alone had minimal antitumor effect (Table18). However, the data generated during the course of the development ofthe present invention shows that (−)-gossypol sensitizes PC-3 cells toradiation therapy in the xenograft animal model. (−)-Gossypol treatmentwas started at day 13 where the average tumor volume was at 150 mm³ andwas given orally at five times weekly in doses of 10 mg/kg for 4 weeks.X-ray irradiation was given at day 5 after treatment with (−)-gossypol.Radiation therapy alone achieved limited antitumor effect (23%).Radiation therapy in combination with administration of gossypol (at thesame dose level (10 mg/kg)) provided potent tumor growth inhibition (88%growth inhibition).

TABLE 18 Tumor Growth Tumor Growth Inhibition Delay Treatment (T/C %) (T− C Days) Radiation 77.7 8.5 (−)-gossypol 98.6 0 Radiation +(−)-gossypol 12.6 54.5

Overall, there was more than 90% inhibition in tumor cell growth inanimals receiving radiation therapy in combination with gossypol ascompared to the group controls (FIG. 36). Briefly, in FIG. 36 day 0 isthe starting day of (−)-gossypol treatment; starting tumor size was 150mm³; (−)-gossypol was administered at 10 mg/kg, orally 5 times per weekfor 4 weeks; radiation: X-ray, 2 Gy, 5 times per week for 3 weeks (atthe second week the radiation was adjusted to 2.5 Gy) for a total doseof 30 Gy. Significantly, there was no significant toxicity in eithergroup as shown by bodyweight measurements (FIG. 37). At the end oftreatment (day 25), one mouse from each single agent and combinationtherapy group was sacrificed and tumor tissues were stained for bothapoptosis and angiogenesis analysis. The results showed that(−)-gossypol was very effective in potentiating radiation in combinationtreatment regimens to induce apoptosis and to inhibit angiogenesis evenat dose levels where it was not very effective as a single agent.

Example 20 Administration of Gossypol Compounds and Radiation Therapy inan In Vivo Mouse PC-3 Xenograft Model

In this experiment, 60 male 5 to 6 week old NCI athymic NCr-nu/nu nudemice were inoculated in each flank with an injection of about 5×10⁶ PC-3cells. The best 40 xenograft recipients were used. Tumors averaged about70 mm³. (−)-Gossypol compounds were first dissolved in ethanol anddiluted with sterile water within 5 min to a final ethanol concentrationof 10% prior to each administration. Irradiated test animals wererestrained, placed under the X-ray head, and covered with lead shieldsto ensure that the tumor area was exposed to radiation. All oraladministrations of (−)-gossypol and 10% alcohol were given by gavage.

The 40 best xenograft mice were divided into experimental groups asfollows: radiation only (Groups 1 and 2), 2 Gy administered 5 times/weekfor 3 weeks, and daily oral administration of 10% alcohol (as vehiclecontrol); radiation plus gossypol (Groups 3 and 4), 2 Gy administered 5times a week for 3 weeks, and 10 mg/kg of (−)-gossypol administeredorally 5 times/week for 4 weeks (8 mice each Group); gossypol only(Groups 5 and 6), 10 mg/kg (−)-gossypol administered orally every dayfor 4 weeks (8 mice each Group); vehicle control (Groups 7 and 8), dailyoral administration of 10% alcohol (8 mice each Group as vehiclecontrol); large tumor animals (combination of Groups 9-12), tumorsallowed to reach 500 mm³.

FIG. 38 shows yet another embodiment wherein (−)-gossypol in combinationwith radiation achieves tumor regression in an androgen-independentprostate PC-3 xenograft model, wherein: day 0 is the starting day ofgossypol treatment; starting tumor size: 70 mm³; (−)-gossypol 10 mg/kg,p.o., q.d.×5, for 4 weeks; radiation, X-ray, 2 Gy, q.d.×5 for 3 weeks,total dose=30 Gy; large tumors in the vehicle control group weresacrificed when they reached over 2-3,000 mm³.

At least 10 out of 16 tumors in the combination group exhibited completeregression with only tiny scars left (from peak tumor sizes of 200 mm³).Other remaining tumors in this group appear pale yellowish and soft ascompared with that in control group with hard solid and reddishappearance, indicating tumor blood supply was inhibited.

Example 21 (−)-Gossypol Inhibits Prostate Cancer Cell Growth

(−)-Gossypol is 5-10 times more potent than (+)-gossypol and 2 timesmore potent than racemic gossypol (50% (−)-gossypol) in inhibitingcancer cell growth in human prostate cancer cells PC-3 and LnCap (FIG.39) both of which express high levels of Bcl-X_(L). FIG. 39 showsprostate cancer cell growth inhibition by gossypol; PC-3 and LnCap cellsin 96 well plates were treated in triplicate with gossypol and itsenantiomers; MTT-based 5-day cell proliferation assays were performedand IC₅₀ values determined. The present invention is not limited to anymechanism. Indeed, a mechanistic understanding of the invention isunnecessary to practice (make and use) the present compositions andmethods. Nonetheless, data generated during the course of thedevelopment of the present invention using 10 head-neck cancer celllines shows that the ability of (−)-gossypol to inhibit cell growth isinversely related to the level of Bcl-xL protein, i.e., the higher thelevel of Bcl-X_(L) protein, the more sensitive the cells (e.g., cancercells) are to (−)-gossypol. The activity profile of (−)-gossypol isdifferent from that of chemotherapeutic agents, which often showresistance in cancer cell lines with high levels of Bcl-X_(L) and Bcl-2proteins. Further in vitro studies demonstrated that (−)-gossypolinduces apoptosis in variety of cancer cell lines with high expressionlevels of Bcl-xL and achieves synergistic effects with docetaxel(TAXOTERE, TXT). In the human prostate cancer cell line PC-3, which hashigh levels of Bcl-X_(L) and Bcl-2 proteins, (−)-gossypol enhanced theactivities of docetaxel and cisplatin (CDDP) in inhibiting cell growthand inducing apoptosis (FIG. 40). Briefly, in FIG. 40, cells weretreated with (−)-gossypol alone or in combination with TXT or CDDP for48 hrs, then stained with Annexin V-FITC and PI for flow cytometry;values are percent of apoptotic cells. FIG. 41 shows the Bcl-2 familyproteins expression in three prostate cancer cell lines; HSP70 heatshock protein 70 kDa fro gel loading. FIG. 42 shows cytotoxicity of(−)-gossypol on prostate cancer cell lines; MTT based 5-day cellproliferation assays were performed and IC₅₀ values determined.(−)-Gossypol while showing cytotoxicity in prostate cancer PC-3 andLnCap cells, has very limited effect on DU145 and normal humanfibroblast WI-38 cells (FIG. 42).

Example 22 Anti-Tumor Activity of (−)-Gossypol Alone and in Combinationwith Docetaxel in Androgen Independent Prostate Cancer PC-3 XenograftModel

Further embodiments of the present invention provide studies of(−)-gossypol using a PC-3 xenograft model in nude mice to evaluate(−)-gossypol's anti-tumor activity in vivo alone and in combination withdocetaxel. In some experiments, the antitumor efficacy of (−)-gossypolwas compared with that of racemic gossypol. Data generated during thedevelopment of the present invention shows that (−)-gossypol issignificantly more potent in tumor growth inhibition than racemicgossypol (50% (−)-gossypol) (FIGS. 43A and 43B). Briefly, in FIG. 43A,15 mg/kg (±)- or (−)-gossypol p.o. was administered to a PC-3 nude mousexenograft model for 26 days; (−)-gossypol is more potent than(±)-gossypol (P<0.001). FIG. 43B shows tumor inhibition by (−)-gossypolwas significantly enhanced when used in combination with docetaxel(TXT); (−)-gossypol (7.5 mg/kg, p.o. daily for 4 weeks) or docetaxel(7.5 mg/kg once a week for 3 weeks); ** student's t-test. Whiledocetaxel alone did not achieve complete tumor regression, (−)-gossypolalone achieved complete tumor regression in 2 out of 12 tumors after the4-week-treatment (Table 19).

TABLE 19 Treatment Complete tumor regression/Total Percent regressionVehicle Control 0/16 0% (−)-gossypol 2/12 17%  (−)-gossypol + TXT 9/1464%* TXT 0/16 0% *(−)-gossypol + TXT versus (−)-gossypol, p = 0.0143;(−)-gossypol + TXT versus TXT, p = 0.0001; two sided Chi-square testWhen used in combination with docetaxel, over 90% of tumor growthinhibition was observed, significantly more effective than either drugalone (FIG. 43B). Nine out of 14 tumors (64%) treated with thecombination of (−)-gossypol+TXT showed complete tumor regression withonly scar tissue left. Six out of these 9 regressed tumors did not growback 8 weeks after the combination therapy ended. Data generated duringthe course of development of the present invention indicates(−)-gossypol has a potent anti-tumor activity in theandrogen-independent human prostate cancer PC-3 xenograft model, andachieves much greater anticancer efficacy in vivo when used incombination with docetaxel (64% complete tumor regression).

Example 23 Blocking of Heterodimerization by (−)-Gossypol in HT-29 ColonCancer Cells

In one embodiment HT-29 colon cancer cells, which express only theBcl-xL protein, were treated with (−)-gossypol at various doses for 4hrs, 8 hrs, and 12 hrs. To avoid the detergent effects on thedimerization of Bcl-xL proteins in immunoprecipitation experiments,following the treatment of cells with gossypol, immunoprecipitation ofcell lysates was carried out in the Chaps buffer with the anti-Bcl-X_(L)antibody. The Bcl-X_(L) bound proteins were then immunoblotted withanti-Bim antibody. Treatment with (−)-gossypol resulted in adose-dependent decrease in the binding of Bcl-X_(L) and pro-apoptoticprotein Bim, starting at 8 hrs following the gossypol treatment (FIG.44). There is no change in the total Bcl-X_(L) or Bim protein in thesame lysates following the (−)-gossypol treatment. These results areconsistent with in vitro binding data (FP-based displacement assay andNMR binding assay) and cellular activity of gossypol at similar dosesand support the notion that (−)-gossypol can enter the cells and has theability to inhibit the interaction of Bcl-X_(L) with pro-apoptoticproteins such as Bim in intact cells.

Example 24 Synthesis of Other Gossypol Compounds

Many simple gossypol compounds have been described in literature (Seee.g., L. D. David et al., Current Medicinal Chemistry, 7:479-498(2000)). The synthesis of apogossypol, gossypolone, and several othergossypol compounds has been carried out by the inventors and is providedbelow.

Synthesis of Apogossypol

Synthetic methods of preparing apogossypol have been reported (See e.g.,P. C. Meltzer et al., J. Org. Chem., 50(17):3121-3124 (1985)). Briefly,apogossypol was prepared by heating racemic gossypol (1.6 g) in aqueousNaOH (40%, 10 mL) at 85° C. for 2 hrs under the protection of nitrogen.The reaction mixture was then cooled down, poured into a mixture of iceand sulfuric acid (from 15 g of concentrated H₂SO₄), the resultant wasextracted with ether twice, and the combined organic phase was washedwith water, dried over anhydrous Na₂SO₄, and concentrated in vacuum toyield apogossypol.

Synthesis of Gossypolone

Synthetic methods of preparing gossypolone have been reported (See e.g.,R. H. Hass et al., J. Org. Chem., 30:4111-4113 (1965)). Briefly, asolution of 2.0 g (3.5 mmol) of gossypol acetic acid purchased from acommercial supplier (e.g., Sigma-Aldrich) in 100 ml of acetone and 200ml of acetic acid was stirred at room temperature during the addition of150 ml of a 10% aqueous solution of ferric chloride hexahydrate (56mmol) and stirring was maintained for 12 hrs. The solution was cooledand 250 ml of water was added to precipitate a dark iron-containingcompound which was removed and treated with a mixture of ether andaqueous 20% sulfuric acid. The liberated phenol was taken into the etherlayer. The ether layer was separated and dried, and the ether wasevaporated. The residue was recrystallized from aqueous acetic acid toyield 1.2 g of orange product.

All publications, patent applications, and patents mentioned in theabove specification are herein incorporated by reference. Variousmodifications and variations of the described method and system of theinvention will be apparent to those skilled in the art without departingfrom the scope and spirit of the invention. Although the invention hasbeen described in connection with specific preferred embodiments, itshould be understood that the invention as claimed should not be undulylimited to such specific embodiments. Indeed, various modifications ofthe described modes for carrying out the invention that are obvious tothose skilled in the relevant fields are intended to be within the scopeof the following claims.

1.-51. (canceled)
 52. A method of treating, ameliorating, or preventinga hyperproliferative disease in a subject comprising administering tosaid subject a therapeutically effective dose of (−)-gossypol and one ormore second agent(s) selected from the group consisting of docetaxel,paclitaxel, cisplatin, radiation therapy, and combinations thereof. 53.The method of claim 52, wherein said hyperproliferative disease iscancer.
 54. The method of claim 53, wherein said cancer is selected fromthe group consisting of breast cancer, prostate cancer, lymphoma, skincancer, pancreatic cancer, colon cancer, melanoma, malignant melanoma,ovarian cancer, brain cancer, primary brain carcinoma, head-neck cancer,glioma, glioblastoma, liver cancer, bladder cancer, non-small cell lungcancer, head or neck carcinoma, breast carcinoma, ovarian carcinoma,lung carcinoma, small-cell lung carcinoma, Wilms' tumor, cervicalcarcinoma, testicular carcinoma, bladder carcinoma, pancreaticcarcinoma, stomach carcinoma, colon carcinoma, prostatic carcinoma,genitourinary carcinoma, thyroid carcinoma, esophageal carcinoma,myeloma, multiple myeloma, adrenal carcinoma, renal cell carcinoma,endometrial carcinoma, adrenal cortex carcinoma, malignant pancreaticinsulinoma, malignant carcinoid carcinoma, choriocarcinoma, mycosisfungoides, malignant hypercalcemia, cervical hyperplasia, leukemia,acute lymphocytic leukemia, chronic lymphocytic leukemia, acutemyelogenous leukemia, chronic myelogenous leukemia, chronic granulocyticleukemia, acute granulocytic leukemia, hairy cell leukemia,neuroblastoma, rhabdomyosarcoma, Kaposi's sarcoma, polycythemia vera,essential thrombocytosis, Hodgkin's disease, non-Hodgkin's lymphoma,soft-tissue sarcoma, osteogenic sarcoma, primary macroglobulinemia, andretinoblastoma.
 55. The method of claim 54, wherein said cancer isselected from the group consisting of breast cancer, prostate cancer,pancreatic cancer, colon cancer, lung cancer, lymphoma, melanoma, andhead-neck cancer.
 56. The method of claim 55, wherein said cancer isselected from the group consisting of breast cancer and prostate cancer.57. The method of claim 52, wherein said one or more additionaltherapeutic agent(s) is selected from the group consisting of docetaxeland paclitaxel.
 58. The method of claim 52, wherein said subject ishuman.
 59. A method of treating or ameliorating breast cancer orprostate cancer in a subject comprising administering to said subject atherapeutically effective dose of (−)-gossypol and docetaxel orpaclitaxel.